Merge branch 'master'

6 files changed, 342 insertions, 280 deletions

diff --git a/drivers/isdn/gigaset/bas-gigaset.c b/drivers/isdn/gigaset/bas-gigaset.c
index f86ed6af3aa2..eb41aba3ddef 100644
--- a/drivers/isdn/gigaset/bas-gigaset.c
+++ b/drivers/isdn/gigaset/bas-gigaset.c
@@ -5,8 +5,6 @@
  *                       Tilman Schmidt <tilman@imap.cc>,
  *                       Stefan Eilers.
  *
- * Based on usb-gigaset.c.
- *
  * =====================================================================
  *      This program is free software; you can redistribute it and/or
  *      modify it under the terms of the GNU General Public License as
@@ -46,19 +44,20 @@ MODULE_PARM_DESC(cidmode, "Call-ID mode");
 #define GIGASET_DEVFSNAME  "gig/bas/"
 #define GIGASET_DEVNAME    "ttyGB"
 
-#define IF_WRITEBUF 256 //FIXME
+/* length limit according to Siemens 3070usb-protokoll.doc ch. 2.1 */
+#define IF_WRITEBUF 264
 
 /* Values for the Gigaset 307x */
 #define USB_GIGA_VENDOR_ID      0x0681
-#define USB_GIGA_PRODUCT_ID     0x0001
-#define USB_4175_PRODUCT_ID     0x0002
+#define USB_3070_PRODUCT_ID     0x0001
+#define USB_3075_PRODUCT_ID     0x0002
 #define USB_SX303_PRODUCT_ID    0x0021
 #define USB_SX353_PRODUCT_ID    0x0022
 
 /* table of devices that work with this driver */
 static struct usb_device_id gigaset_table [] = {
-        { USB_DEVICE(USB_GIGA_VENDOR_ID, USB_GIGA_PRODUCT_ID) },
-        { USB_DEVICE(USB_GIGA_VENDOR_ID, USB_4175_PRODUCT_ID) },
+        { USB_DEVICE(USB_GIGA_VENDOR_ID, USB_3070_PRODUCT_ID) },
+        { USB_DEVICE(USB_GIGA_VENDOR_ID, USB_3075_PRODUCT_ID) },
         { USB_DEVICE(USB_GIGA_VENDOR_ID, USB_SX303_PRODUCT_ID) },
         { USB_DEVICE(USB_GIGA_VENDOR_ID, USB_SX353_PRODUCT_ID) },
         { } /* Terminating entry */
@@ -77,6 +76,10 @@ static int gigaset_probe(struct usb_interface *interface,
 /* Function will be called if the device is unplugged */
 static void gigaset_disconnect(struct usb_interface *interface);
 
+static void read_ctrl_callback(struct urb *, struct pt_regs *);
+static void stopurbs(struct bas_bc_state *);
+static int atwrite_submit(struct cardstate *, unsigned char *, int);
+static int start_cbsend(struct cardstate *);
 
 /*==============================================================================*/
 
@@ -111,12 +114,14 @@ struct bas_cardstate {
 };
 
 /* status of direct USB connection to 307x base (bits in basstate) */
-#define BS_ATOPEN       0x001
-#define BS_B1OPEN       0x002
-#define BS_B2OPEN       0x004
-#define BS_ATREADY      0x008
-#define BS_INIT         0x010
-#define BS_ATTIMER      0x020
+#define BS_ATOPEN       0x001   /* AT channel open */
+#define BS_B1OPEN       0x002   /* B channel 1 open */
+#define BS_B2OPEN       0x004   /* B channel 2 open */
+#define BS_ATREADY      0x008   /* base ready for AT command */
+#define BS_INIT         0x010   /* base has signalled INIT_OK */
+#define BS_ATTIMER      0x020   /* waiting for HD_READY_SEND_ATDATA */
+#define BS_ATRDPEND     0x040   /* urb_cmd_in in use */
+#define BS_ATWRPEND     0x080   /* urb_cmd_out in use */
 
 
 static struct gigaset_driver *driver = NULL;
@@ -130,6 +135,47 @@ static struct usb_driver gigaset_usb_driver = {
         .id_table =     gigaset_table,
 };
 
+/* get message text for usb_submit_urb return code
+ */
+static char *get_usb_rcmsg(int rc)
+{
+        static char unkmsg[28];
+
+        switch (rc) {
+        case 0:
+                return "success";
+        case -ENOMEM:
+                return "out of memory";
+        case -ENODEV:
+                return "device not present";
+        case -ENOENT:
+                return "endpoint not present";
+        case -ENXIO:
+                return "URB type not supported";
+        case -EINVAL:
+                return "invalid argument";
+        case -EAGAIN:
+                return "start frame too early or too much scheduled";
+        case -EFBIG:
+                return "too many isochronous frames requested";
+        case -EPIPE:
+                return "endpoint stalled";
+        case -EMSGSIZE:
+                return "invalid packet size";
+        case -ENOSPC:
+                return "would overcommit USB bandwidth";
+        case -ESHUTDOWN:
+                return "device shut down";
+        case -EPERM:
+                return "reject flag set";
+        case -EHOSTUNREACH:
+                return "device suspended";
+        default:
+                snprintf(unkmsg, sizeof(unkmsg), "unknown error %d", rc);
+                return unkmsg;
+        }
+}
+
 /* get message text for USB status code
  */
 static char *get_usb_statmsg(int status)
@@ -140,43 +186,37 @@ static char *get_usb_statmsg(int status)
         case 0:
                 return "success";
         case -ENOENT:
-                return "canceled";
-        case -ECONNRESET:
-                return "canceled (async)";
+                return "unlinked (sync)";
         case -EINPROGRESS:
                 return "pending";
         case -EPROTO:
-                return "bit stuffing or unknown USB error";
+                return "bit stuffing error, timeout, or unknown USB error";
         case -EILSEQ:
-                return "Illegal byte sequence (CRC mismatch)";
-        case -EPIPE:
-                return "babble detect or endpoint stalled";
-        case -ENOSR:
-                return "buffer error";
+                return "CRC mismatch, timeout, or unknown USB error";
         case -ETIMEDOUT:
                 return "timed out";
-        case -ENODEV:
-                return "device not present";
+        case -EPIPE:
+                return "endpoint stalled";
+        case -ECOMM:
+                return "IN buffer overrun";
+        case -ENOSR:
+                return "OUT buffer underrun";
+        case -EOVERFLOW:
+                return "too much data";
         case -EREMOTEIO:
                 return "short packet detected";
+        case -ENODEV:
+                return "device removed";
         case -EXDEV:
                 return "partial isochronous transfer";
         case -EINVAL:
                 return "invalid argument";
-        case -ENXIO:
-                return "URB already queued";
-        case -EAGAIN:
-                return "isochronous start frame too early or too much scheduled";
-        case -EFBIG:
-                return "too many isochronous frames requested";
-        case -EMSGSIZE:
-                return "endpoint message size zero";
+        case -ECONNRESET:
+                return "unlinked (async)";
         case -ESHUTDOWN:
-                return "endpoint shutdown";
-        case -EBUSY:
-                return "another request pending";
+                return "device shut down";
         default:
-                snprintf(unkmsg, sizeof(unkmsg), "unknown error %d", status);
+                snprintf(unkmsg, sizeof(unkmsg), "unknown status %d", status);
                 return unkmsg;
         }
 }
@@ -277,18 +317,17 @@ static inline void error_hangup(struct bc_state *bcs)
         gig_dbg(DEBUG_ANY, "%s: scheduling HUP for channel %d",
                 __func__, bcs->channel);
 
-        if (!gigaset_add_event(cs, &bcs->at_state, EV_HUP, NULL, 0, NULL)) {
-                //FIXME what should we do?
-                return;
-        }
+        if (!gigaset_add_event(cs, &bcs->at_state, EV_HUP, NULL, 0, NULL))
+                dev_err(cs->dev, "event queue full\n");
 
         gigaset_schedule_event(cs);
 }
 
 /* error_reset
  * reset Gigaset device because of an unrecoverable error
- * This function may be called from any context and takes care of scheduling
- * the necessary actions for execution outside of interrupt context.
+ * This function may be called from any context, and should take care of
+ * scheduling the necessary actions for execution outside of interrupt context.
+ * Right now, it just generates a kernel message calling for help.
  * argument:
  *      controller state structure
  */
@@ -364,36 +403,38 @@ static void cmd_in_timeout(unsigned long data)
 {
         struct cardstate *cs = (struct cardstate *) data;
         struct bas_cardstate *ucs = cs->hw.bas;
-        unsigned long flags;
 
-        spin_lock_irqsave(&cs->lock, flags);
-        if (unlikely(!cs->connected)) {
-                gig_dbg(DEBUG_USBREQ, "%s: disconnected", __func__);
-                spin_unlock_irqrestore(&cs->lock, flags);
-                return;
-        }
         if (!ucs->rcvbuf_size) {
                 gig_dbg(DEBUG_USBREQ, "%s: no receive in progress", __func__);
-                spin_unlock_irqrestore(&cs->lock, flags);
                 return;
         }
-        spin_unlock_irqrestore(&cs->lock, flags);
 
         dev_err(cs->dev, "timeout reading AT response\n");
         error_reset(cs);        //FIXME retry?
 }
 
+/* set/clear bits in base connection state, return previous state
+ */
+inline static int update_basstate(struct bas_cardstate *ucs,
+                                  int set, int clear)
+{
+        unsigned long flags;
+        int state;
 
-static void read_ctrl_callback(struct urb *urb, struct pt_regs *regs);
+        spin_lock_irqsave(&ucs->lock, flags);
+        state = atomic_read(&ucs->basstate);
+        atomic_set(&ucs->basstate, (state & ~clear) | set);
+        spin_unlock_irqrestore(&ucs->lock, flags);
+        return state;
+}
 
 /* atread_submit
- * submit an HD_READ_ATMESSAGE command URB
+ * submit an HD_READ_ATMESSAGE command URB and optionally start a timeout
  * parameters:
  *      cs      controller state structure
  *      timeout timeout in 1/10 sec., 0: none
  * return value:
  *      0 on success
- *      -EINVAL if a NULL pointer is encountered somewhere
  *      -EBUSY if another request is pending
  *      any URB submission error code
  */
@@ -405,7 +446,7 @@ static int atread_submit(struct cardstate *cs, int timeout)
         gig_dbg(DEBUG_USBREQ, "-------> HD_READ_ATMESSAGE (%d)",
                 ucs->rcvbuf_size);
 
-        if (ucs->urb_cmd_in->status == -EINPROGRESS) {
+        if (update_basstate(ucs, BS_ATRDPEND, 0) & BS_ATRDPEND) {
                 dev_err(cs->dev,
                         "could not submit HD_READ_ATMESSAGE: URB busy\n");
                 return -EBUSY;
@@ -423,6 +464,7 @@ static int atread_submit(struct cardstate *cs, int timeout)
                              read_ctrl_callback, cs->inbuf);
 
         if ((ret = usb_submit_urb(ucs->urb_cmd_in, SLAB_ATOMIC)) != 0) {
+                update_basstate(ucs, 0, BS_ATRDPEND);
                 dev_err(cs->dev, "could not submit HD_READ_ATMESSAGE: %s\n",
                         get_usb_statmsg(ret));
                 return ret;
@@ -438,26 +480,6 @@ static int atread_submit(struct cardstate *cs, int timeout)
         return 0;
 }
 
-static void stopurbs(struct bas_bc_state *);
-static int start_cbsend(struct cardstate *);
-
-/* set/clear bits in base connection state
- */
-inline static void update_basstate(struct bas_cardstate *ucs,
-                                   int set, int clear)
-{
-        unsigned long flags;
-        int state;
-
-        spin_lock_irqsave(&ucs->lock, flags);
-        state = atomic_read(&ucs->basstate);
-        state &= ~clear;
-        state |= set;
-        atomic_set(&ucs->basstate, state);
-        spin_unlock_irqrestore(&ucs->lock, flags);
-}
-
-
 /* read_int_callback
  * USB completion handler for interrupt pipe input
  * called by the USB subsystem in interrupt context
@@ -471,20 +493,25 @@ static void read_int_callback(struct urb *urb, struct pt_regs *regs)
         struct bas_cardstate *ucs = cs->hw.bas;
         struct bc_state *bcs;
         unsigned long flags;
-        int status;
+        int rc;
         unsigned l;
         int channel;
 
         switch (urb->status) {
         case 0:                 /* success */
                 break;
-        case -ENOENT:                   /* canceled */
-        case -ECONNRESET:               /* canceled (async) */
+        case -ENOENT:                   /* cancelled */
+        case -ECONNRESET:               /* cancelled (async) */
         case -EINPROGRESS:              /* pending */
                 /* ignore silently */
                 gig_dbg(DEBUG_USBREQ, "%s: %s",
                         __func__, get_usb_statmsg(urb->status));
                 return;
+        case -ENODEV:                   /* device removed */
+        case -ESHUTDOWN:                /* device shut down */
+                //FIXME use this as disconnect indicator?
+                gig_dbg(DEBUG_USBREQ, "%s: device disconnected", __func__);
+                return;
         default:                /* severe trouble */
                 dev_warn(cs->dev, "interrupt read: %s\n",
                          get_usb_statmsg(urb->status));
@@ -492,6 +519,13 @@ static void read_int_callback(struct urb *urb, struct pt_regs *regs)
                 goto resubmit;
         }
 
+        /* drop incomplete packets even if the missing bytes wouldn't matter */
+        if (unlikely(urb->actual_length < 3)) {
+                dev_warn(cs->dev, "incomplete interrupt packet (%d bytes)\n",
+                         urb->actual_length);
+                goto resubmit;
+        }
+
         l = (unsigned) ucs->int_in_buf[1] +
             (((unsigned) ucs->int_in_buf[2]) << 8);
 
@@ -558,25 +592,28 @@ static void read_int_callback(struct urb *urb, struct pt_regs *regs)
                 }
                 spin_lock_irqsave(&cs->lock, flags);
                 if (ucs->rcvbuf_size) {
-                        spin_unlock_irqrestore(&cs->lock, flags);
+                        /* throw away previous buffer - we have no queue */
                         dev_err(cs->dev,
-                                "receive AT data overrun, %d bytes lost\n", l);
-                        error_reset(cs);        //FIXME reschedule
-                        break;
+                                "receive AT data overrun, %d bytes lost\n",
+                                ucs->rcvbuf_size);
+                        kfree(ucs->rcvbuf);
+                        ucs->rcvbuf_size = 0;
                 }
                 if ((ucs->rcvbuf = kmalloc(l, GFP_ATOMIC)) == NULL) {
                         spin_unlock_irqrestore(&cs->lock, flags);
-                        dev_err(cs->dev, "out of memory, %d bytes lost\n", l);
-                        error_reset(cs);        //FIXME reschedule
+                        dev_err(cs->dev, "out of memory receiving AT data\n");
+                        error_reset(cs);
                         break;
                 }
                 ucs->rcvbuf_size = l;
                 ucs->retry_cmd_in = 0;
-                if ((status = atread_submit(cs, BAS_TIMEOUT)) < 0) {
+                if ((rc = atread_submit(cs, BAS_TIMEOUT)) < 0) {
                         kfree(ucs->rcvbuf);
                         ucs->rcvbuf = NULL;
                         ucs->rcvbuf_size = 0;
-                        error_reset(cs);        //FIXME reschedule
+                        if (rc != -ENODEV)
+                                //FIXME corrective action?
+                                error_reset(cs);
                 }
                 spin_unlock_irqrestore(&cs->lock, flags);
                 break;
@@ -598,12 +635,10 @@ static void read_int_callback(struct urb *urb, struct pt_regs *regs)
         check_pending(ucs);
 
 resubmit:
-        spin_lock_irqsave(&cs->lock, flags);
-        status = cs->connected ? usb_submit_urb(urb, SLAB_ATOMIC) : -ENODEV;
-        spin_unlock_irqrestore(&cs->lock, flags);
-        if (unlikely(status)) {
+        rc = usb_submit_urb(urb, SLAB_ATOMIC);
+        if (unlikely(rc != 0 && rc != -ENODEV)) {
                 dev_err(cs->dev, "could not resubmit interrupt URB: %s\n",
-                        get_usb_statmsg(status));
+                        get_usb_rcmsg(rc));
                 error_reset(cs);
         }
 }
@@ -622,18 +657,12 @@ static void read_ctrl_callback(struct urb *urb, struct pt_regs *regs)
         struct bas_cardstate *ucs = cs->hw.bas;
         int have_data = 0;
         unsigned numbytes;
-        unsigned long flags;
+        int rc;
 
-        spin_lock_irqsave(&cs->lock, flags);
-        if (unlikely(!cs->connected)) {
-                warn("%s: disconnected", __func__);
-                spin_unlock_irqrestore(&cs->lock, flags);
-                return;
-        }
+        update_basstate(ucs, 0, BS_ATRDPEND);
 
         if (!ucs->rcvbuf_size) {
                 dev_warn(cs->dev, "%s: no receive in progress\n", __func__);
-                spin_unlock_irqrestore(&cs->lock, flags);
                 return;
         }
 
@@ -666,9 +695,11 @@ static void read_ctrl_callback(struct urb *urb, struct pt_regs *regs)
                 }
                 break;
 
-        case -ENOENT:                   /* canceled */
-        case -ECONNRESET:               /* canceled (async) */
+        case -ENOENT:                   /* cancelled */
+        case -ECONNRESET:               /* cancelled (async) */
         case -EINPROGRESS:              /* pending */
+        case -ENODEV:                   /* device removed */
+        case -ESHUTDOWN:                /* device shut down */
                 /* no action necessary */
                 gig_dbg(DEBUG_USBREQ, "%s: %s",
                         __func__, get_usb_statmsg(urb->status));
@@ -681,11 +712,11 @@ static void read_ctrl_callback(struct urb *urb, struct pt_regs *regs)
                 if (ucs->retry_cmd_in++ < BAS_RETRY) {
                         dev_notice(cs->dev, "control read: retry %d\n",
                                    ucs->retry_cmd_in);
-                        if (atread_submit(cs, BAS_TIMEOUT) >= 0) {
-                                /* resubmitted - bypass regular exit block */
-                                spin_unlock_irqrestore(&cs->lock, flags);
+                        rc = atread_submit(cs, BAS_TIMEOUT);
+                        if (rc >= 0 || rc == -ENODEV)
+                                /* resubmitted or disconnected */
+                                /* - bypass regular exit block */
                                 return;
-                        }
                 } else {
                         dev_err(cs->dev,
                                 "control read: giving up after %d tries\n",
@@ -697,7 +728,6 @@ static void read_ctrl_callback(struct urb *urb, struct pt_regs *regs)
         kfree(ucs->rcvbuf);
         ucs->rcvbuf = NULL;
         ucs->rcvbuf_size = 0;
-        spin_unlock_irqrestore(&cs->lock, flags);
         if (have_data) {
                 gig_dbg(DEBUG_INTR, "%s-->BH", __func__);
                 gigaset_schedule_event(cs);
@@ -719,8 +749,11 @@ static void read_iso_callback(struct urb *urb, struct pt_regs *regs)
         int i, rc;
 
         /* status codes not worth bothering the tasklet with */
-        if (unlikely(urb->status == -ENOENT || urb->status == -ECONNRESET ||
-                     urb->status == -EINPROGRESS)) {
+        if (unlikely(urb->status == -ENOENT ||
+                     urb->status == -ECONNRESET ||
+                     urb->status == -EINPROGRESS ||
+                     urb->status == -ENODEV ||
+                     urb->status == -ESHUTDOWN)) {
                 gig_dbg(DEBUG_ISO, "%s: %s",
                         __func__, get_usb_statmsg(urb->status));
                 return;
@@ -740,9 +773,9 @@ static void read_iso_callback(struct urb *urb, struct pt_regs *regs)
                 for (i = 0; i < BAS_NUMFRAMES; i++) {
                         ubc->isoinlost += urb->iso_frame_desc[i].actual_length;
                         if (unlikely(urb->iso_frame_desc[i].status != 0 &&
-                                     urb->iso_frame_desc[i].status != -EINPROGRESS)) {
+                                     urb->iso_frame_desc[i].status !=
+                                                                -EINPROGRESS))
                                 ubc->loststatus = urb->iso_frame_desc[i].status;
-                        }
                         urb->iso_frame_desc[i].status = 0;
                         urb->iso_frame_desc[i].actual_length = 0;
                 }
@@ -754,10 +787,10 @@ static void read_iso_callback(struct urb *urb, struct pt_regs *regs)
                         gig_dbg(DEBUG_ISO, "%s: isoc read overrun/resubmit",
                                 __func__);
                         rc = usb_submit_urb(urb, SLAB_ATOMIC);
-                        if (unlikely(rc != 0)) {
+                        if (unlikely(rc != 0 && rc != -ENODEV)) {
                                 dev_err(bcs->cs->dev,
                                         "could not resubmit isochronous read "
-                                        "URB: %s\n", get_usb_statmsg(rc));
+                                        "URB: %s\n", get_usb_rcmsg(rc));
                                 dump_urb(DEBUG_ISO, "isoc read", urb);
                                 error_hangup(bcs);
                         }
@@ -780,8 +813,11 @@ static void write_iso_callback(struct urb *urb, struct pt_regs *regs)
         unsigned long flags;
 
         /* status codes not worth bothering the tasklet with */
-        if (unlikely(urb->status == -ENOENT || urb->status == -ECONNRESET ||
-                     urb->status == -EINPROGRESS)) {
+        if (unlikely(urb->status == -ENOENT ||
+                     urb->status == -ECONNRESET ||
+                     urb->status == -EINPROGRESS ||
+                     urb->status == -ENODEV ||
+                     urb->status == -ESHUTDOWN)) {
                 gig_dbg(DEBUG_ISO, "%s: %s",
                         __func__, get_usb_statmsg(urb->status));
                 return;
@@ -822,7 +858,6 @@ static int starturbs(struct bc_state *bcs)
         for (k = 0; k < BAS_INURBS; k++) {
                 urb = ubc->isoinurbs[k];
                 if (!urb) {
-                        dev_err(bcs->cs->dev, "isoinurbs[%d]==NULL\n", k);
                         rc = -EFAULT;
                         goto error;
                 }
@@ -844,12 +879,8 @@ static int starturbs(struct bc_state *bcs)
                 }
 
                 dump_urb(DEBUG_ISO, "Initial isoc read", urb);
-                if ((rc = usb_submit_urb(urb, SLAB_ATOMIC)) != 0) {
-                        dev_err(bcs->cs->dev,
-                               "could not submit isochronous read URB %d: %s\n",
-                                k, get_usb_statmsg(rc));
+                if ((rc = usb_submit_urb(urb, SLAB_ATOMIC)) != 0)
                         goto error;
-                }
         }
 
         /* initialize L2 transmission */
@@ -859,7 +890,6 @@ static int starturbs(struct bc_state *bcs)
         for (k = 0; k < BAS_OUTURBS; ++k) {
                 urb = ubc->isoouturbs[k].urb;
                 if (!urb) {
-                        dev_err(bcs->cs->dev, "isoouturbs[%d].urb==NULL\n", k);
                         rc = -EFAULT;
                         goto error;
                 }
@@ -885,12 +915,8 @@ static int starturbs(struct bc_state *bcs)
         for (k = 0; k < 2; ++k) {
                 dump_urb(DEBUG_ISO, "Initial isoc write", urb);
                 rc = usb_submit_urb(ubc->isoouturbs[k].urb, SLAB_ATOMIC);
-                if (rc != 0) {
-                        dev_err(bcs->cs->dev,
-                              "could not submit isochronous write URB %d: %s\n",
-                                k, get_usb_statmsg(rc));
+                if (rc != 0)
                         goto error;
-                }
         }
         dump_urb(DEBUG_ISO, "Initial isoc write (free)", urb);
         ubc->isooutfree = &ubc->isoouturbs[2];
@@ -916,15 +942,15 @@ static void stopurbs(struct bas_bc_state *ubc)
         for (k = 0; k < BAS_INURBS; ++k) {
                 rc = usb_unlink_urb(ubc->isoinurbs[k]);
                 gig_dbg(DEBUG_ISO,
-                        "%s: isoc input URB %d unlinked, result = %d",
-                        __func__, k, rc);
+                        "%s: isoc input URB %d unlinked, result = %s",
+                        __func__, k, get_usb_rcmsg(rc));
         }
 
         for (k = 0; k < BAS_OUTURBS; ++k) {
                 rc = usb_unlink_urb(ubc->isoouturbs[k].urb);
                 gig_dbg(DEBUG_ISO,
-                        "%s: isoc output URB %d unlinked, result = %d",
-                        __func__, k, rc);
+                        "%s: isoc output URB %d unlinked, result = %s",
+                        __func__, k, get_usb_rcmsg(rc));
         }
 }
 
@@ -934,7 +960,7 @@ static void stopurbs(struct bas_bc_state *ubc)
 /* submit_iso_write_urb
  * fill and submit the next isochronous write URB
  * parameters:
- *      bcs     B channel state structure
+ *      ucx     context structure containing URB
  * return value:
  *      number of frames submitted in URB
  *      0 if URB not submitted because no data available (isooutbuf busy)
@@ -946,7 +972,6 @@ static int submit_iso_write_urb(struct isow_urbctx_t *ucx)
         struct bas_bc_state *ubc = ucx->bcs->hw.bas;
         struct usb_iso_packet_descriptor *ifd;
         int corrbytes, nframe, rc;
-        unsigned long flags;
 
         /* urb->dev is clobbered by USB subsystem */
         urb->dev = ucx->bcs->cs->hw.bas->udev;
@@ -992,20 +1017,22 @@ static int submit_iso_write_urb(struct isow_urbctx_t *ucx)
                 ifd->status = 0;
                 ifd->actual_length = 0;
         }
-        if ((urb->number_of_packets = nframe) > 0) {
-                spin_lock_irqsave(&ucx->bcs->cs->lock, flags);
-                rc = ucx->bcs->cs->connected ? usb_submit_urb(urb, SLAB_ATOMIC) : -ENODEV;
-                spin_unlock_irqrestore(&ucx->bcs->cs->lock, flags);
+        if (unlikely(nframe == 0))
+                return 0;       /* no data to send */
+        urb->number_of_packets = nframe;
 
-                if (rc) {
+        rc = usb_submit_urb(urb, SLAB_ATOMIC);
+        if (unlikely(rc)) {
+                if (rc == -ENODEV)
+                        /* device removed - give up silently */
+                        gig_dbg(DEBUG_ISO, "%s: disconnected", __func__);
+                else
                         dev_err(ucx->bcs->cs->dev,
                                 "could not submit isochronous write URB: %s\n",
-                                get_usb_statmsg(rc));
-                        dump_urb(DEBUG_ISO, "isoc write", urb);
-                        return rc;
-                }
-                ++ubc->numsub;
+                                get_usb_rcmsg(rc));
+                return rc;
         }
+        ++ubc->numsub;
         return nframe;
 }
 
@@ -1028,6 +1055,7 @@ static void write_iso_tasklet(unsigned long data)
         int i;
         struct sk_buff *skb;
         int len;
+        int rc;
 
         /* loop while completed URBs arrive in time */
         for (;;) {
@@ -1057,7 +1085,8 @@ static void write_iso_tasklet(unsigned long data)
                 ubc->isooutfree = NULL;
                 spin_unlock_irqrestore(&ubc->isooutlock, flags);
                 if (next) {
-                        if (submit_iso_write_urb(next) <= 0) {
+                        rc = submit_iso_write_urb(next);
+                        if (unlikely(rc <= 0 && rc != -ENODEV)) {
                                 /* could not submit URB, put it back */
                                 spin_lock_irqsave(&ubc->isooutlock, flags);
                                 if (ubc->isooutfree == NULL) {
@@ -1077,17 +1106,18 @@ static void write_iso_tasklet(unsigned long data)
                 /* process completed URB */
                 urb = done->urb;
                 switch (urb->status) {
+                case -EXDEV:                    /* partial completion */
+                        gig_dbg(DEBUG_ISO, "%s: URB partially completed",
+                                __func__);
+                        /* fall through - what's the difference anyway? */
                 case 0:                         /* normal completion */
-                        break;
-                case -EXDEV:                    /* inspect individual frames */
-                        /* assumptions (for lack of documentation):
-                         * - actual_length bytes of the frame in error are
+                        /* inspect individual frames
+                         * assumptions (for lack of documentation):
+                         * - actual_length bytes of first frame in error are
                          *   successfully sent
                          * - all following frames are not sent at all
                          */
-                        gig_dbg(DEBUG_ISO, "%s: URB partially completed",
-                                __func__);
-                        offset = done->limit;   /* just in case */
+                        offset = done->limit;   /* default (no error) */
                         for (i = 0; i < BAS_NUMFRAMES; i++) {
                                 ifd = &urb->iso_frame_desc[i];
                                 if (ifd->status ||
@@ -1122,7 +1152,7 @@ static void write_iso_tasklet(unsigned long data)
                         }
 #endif
                         break;
-                case -EPIPE:            //FIXME is this the code for "underrun"?
+                case -EPIPE:                    /* stall - probably underrun */
                         dev_err(cs->dev, "isochronous write stalled\n");
                         error_hangup(bcs);
                         break;
@@ -1142,7 +1172,8 @@ static void write_iso_tasklet(unsigned long data)
                 spin_unlock_irqrestore(&ubc->isooutlock, flags);
                 if (next) {
                         /* only one URB still active - resubmit one */
-                        if (submit_iso_write_urb(next) <= 0) {
+                        rc = submit_iso_write_urb(next);
+                        if (unlikely(rc <= 0 && rc != -ENODEV)) {
                                 /* couldn't submit */
                                 error_hangup(bcs);
                         }
@@ -1222,10 +1253,9 @@ static void read_iso_tasklet(unsigned long data)
                         break;
                 case -ENOENT:
                 case -ECONNRESET:
-                        gig_dbg(DEBUG_ISO, "%s: URB canceled", __func__);
-                        continue;               /* -> skip */
-                case -EINPROGRESS:              /* huh? */
-                        gig_dbg(DEBUG_ISO, "%s: URB still pending", __func__);
+                case -EINPROGRESS:
+                        gig_dbg(DEBUG_ISO, "%s: %s",
+                                __func__, get_usb_statmsg(urb->status));
                         continue;               /* -> skip */
                 case -EPIPE:
                         dev_err(cs->dev, "isochronous read stalled\n");
@@ -1290,13 +1320,11 @@ static void read_iso_tasklet(unsigned long data)
                 urb->dev = bcs->cs->hw.bas->udev;
                 urb->transfer_flags = URB_ISO_ASAP;
                 urb->number_of_packets = BAS_NUMFRAMES;
-                spin_lock_irqsave(&cs->lock, flags);
-                rc = cs->connected ? usb_submit_urb(urb, SLAB_ATOMIC) : -ENODEV;
-                spin_unlock_irqrestore(&cs->lock, flags);
-                if (rc) {
+                rc = usb_submit_urb(urb, SLAB_ATOMIC);
+                if (unlikely(rc != 0 && rc != -ENODEV)) {
                         dev_err(cs->dev,
                                 "could not resubmit isochronous read URB: %s\n",
-                                get_usb_statmsg(rc));
+                                get_usb_rcmsg(rc));
                         dump_urb(DEBUG_ISO, "resubmit iso read", urb);
                         error_hangup(bcs);
                 }
@@ -1397,7 +1425,6 @@ static void write_ctrl_callback(struct urb *urb, struct pt_regs *regs)
  *      timeout timeout in seconds (0: no timeout)
  * return value:
  *      0 on success
- *      -EINVAL if a NULL pointer is encountered somewhere
  *      -EBUSY if another request is pending
  *      any URB submission error code
  */
@@ -1418,12 +1445,6 @@ static int req_submit(struct bc_state *bcs, int req, int val, int timeout)
                         req, ucs->pending);
                 return -EBUSY;
         }
-        if (ucs->urb_ctrl->status == -EINPROGRESS) {
-                spin_unlock_irqrestore(&ucs->lock, flags);
-                dev_err(bcs->cs->dev,
-                        "could not submit request 0x%02x: URB busy\n", req);
-                return -EBUSY;
-        }
 
         ucs->dr_ctrl.bRequestType = OUT_VENDOR_REQ;
         ucs->dr_ctrl.bRequest = req;
@@ -1465,22 +1486,36 @@ static int req_submit(struct bc_state *bcs, int req, int val, int timeout)
 static int gigaset_init_bchannel(struct bc_state *bcs)
 {
         int req, ret;
+        unsigned long flags;
+
+        spin_lock_irqsave(&bcs->cs->lock, flags);
+        if (unlikely(!bcs->cs->connected)) {
+                gig_dbg(DEBUG_USBREQ, "%s: not connected", __func__);
+                spin_unlock_irqrestore(&bcs->cs->lock, flags);
+                return -ENODEV;
+        }
 
         if ((ret = starturbs(bcs)) < 0) {
                 dev_err(bcs->cs->dev,
-                        "could not start isochronous I/O for channel %d\n",
-                        bcs->channel + 1);
-                error_hangup(bcs);
+                        "could not start isochronous I/O for channel B%d: %s\n",
+                        bcs->channel + 1,
+                        ret == -EFAULT ? "null URB" : get_usb_rcmsg(ret));
+                if (ret != -ENODEV)
+                        error_hangup(bcs);
+                spin_unlock_irqrestore(&bcs->cs->lock, flags);
                 return ret;
         }
 
         req = bcs->channel ? HD_OPEN_B2CHANNEL : HD_OPEN_B1CHANNEL;
         if ((ret = req_submit(bcs, req, 0, BAS_TIMEOUT)) < 0) {
-                dev_err(bcs->cs->dev, "could not open channel %d: %s\n",
-                        bcs->channel + 1, get_usb_statmsg(ret));
+                dev_err(bcs->cs->dev, "could not open channel B%d\n",
+                        bcs->channel + 1);
                 stopurbs(bcs->hw.bas);
-                error_hangup(bcs);
+                if (ret != -ENODEV)
+                        error_hangup(bcs);
         }
+
+        spin_unlock_irqrestore(&bcs->cs->lock, flags);
         return ret;
 }
 
@@ -1497,19 +1532,30 @@ static int gigaset_init_bchannel(struct bc_state *bcs)
 static int gigaset_close_bchannel(struct bc_state *bcs)
 {
         int req, ret;
+        unsigned long flags;
+
+        spin_lock_irqsave(&bcs->cs->lock, flags);
+        if (unlikely(!bcs->cs->connected)) {
+                spin_unlock_irqrestore(&bcs->cs->lock, flags);
+                gig_dbg(DEBUG_USBREQ, "%s: not connected", __func__);
+                return -ENODEV;
+        }
 
         if (!(atomic_read(&bcs->cs->hw.bas->basstate) &
               (bcs->channel ? BS_B2OPEN : BS_B1OPEN))) {
                 /* channel not running: just signal common.c */
+                spin_unlock_irqrestore(&bcs->cs->lock, flags);
                 gigaset_bchannel_down(bcs);
                 return 0;
         }
 
+        /* channel running: tell device to close it */
         req = bcs->channel ? HD_CLOSE_B2CHANNEL : HD_CLOSE_B1CHANNEL;
         if ((ret = req_submit(bcs, req, 0, BAS_TIMEOUT)) < 0)
-                dev_err(bcs->cs->dev,
-                        "could not submit HD_CLOSE_BxCHANNEL request: %s\n",
-                        get_usb_statmsg(ret));
+                dev_err(bcs->cs->dev, "closing channel B%d failed\n",
+                        bcs->channel + 1);
+
+        spin_unlock_irqrestore(&bcs->cs->lock, flags);
         return ret;
 }
 
@@ -1545,8 +1591,6 @@ static void complete_cb(struct cardstate *cs)
         kfree(cb);
 }
 
-static int atwrite_submit(struct cardstate *cs, unsigned char *buf, int len);
-
 /* write_command_callback
  * USB completion handler for AT command transmission
  * called by the USB subsystem in interrupt context
@@ -1560,13 +1604,17 @@ static void write_command_callback(struct urb *urb, struct pt_regs *regs)
         struct bas_cardstate *ucs = cs->hw.bas;
         unsigned long flags;
 
+        update_basstate(ucs, 0, BS_ATWRPEND);
+
         /* check status */
         switch (urb->status) {
         case 0:                                 /* normal completion */
                 break;
-        case -ENOENT:                   /* canceled */
-        case -ECONNRESET:               /* canceled (async) */
+        case -ENOENT:                   /* cancelled */
+        case -ECONNRESET:               /* cancelled (async) */
         case -EINPROGRESS:              /* pending */
+        case -ENODEV:                   /* device removed */
+        case -ESHUTDOWN:                /* device shut down */
                 /* ignore silently */
                 gig_dbg(DEBUG_USBREQ, "%s: %s",
                         __func__, get_usb_statmsg(urb->status));
@@ -1627,19 +1675,17 @@ static void atrdy_timeout(unsigned long data)
  *      len     length of command to send
  * return value:
  *      0 on success
- *      -EFAULT if a NULL pointer is encountered somewhere
  *      -EBUSY if another request is pending
  *      any URB submission error code
  */
 static int atwrite_submit(struct cardstate *cs, unsigned char *buf, int len)
 {
         struct bas_cardstate *ucs = cs->hw.bas;
-        unsigned long flags;
-        int ret;
+        int rc;
 
         gig_dbg(DEBUG_USBREQ, "-------> HD_WRITE_ATMESSAGE (%d)", len);
 
-        if (ucs->urb_cmd_out->status == -EINPROGRESS) {
+        if (update_basstate(ucs, BS_ATWRPEND, 0) & BS_ATWRPEND) {
                 dev_err(cs->dev,
                         "could not submit HD_WRITE_ATMESSAGE: URB busy\n");
                 return -EBUSY;
@@ -1654,29 +1700,22 @@ static int atwrite_submit(struct cardstate *cs, unsigned char *buf, int len)
                              usb_sndctrlpipe(ucs->udev, 0),
                              (unsigned char*) &ucs->dr_cmd_out, buf, len,
                              write_command_callback, cs);
-
-        spin_lock_irqsave(&cs->lock, flags);
-        ret = cs->connected ? usb_submit_urb(ucs->urb_cmd_out, SLAB_ATOMIC) : -ENODEV;
-        spin_unlock_irqrestore(&cs->lock, flags);
-
-        if (ret) {
+        rc = usb_submit_urb(ucs->urb_cmd_out, SLAB_ATOMIC);
+        if (unlikely(rc)) {
+                update_basstate(ucs, 0, BS_ATWRPEND);
                 dev_err(cs->dev, "could not submit HD_WRITE_ATMESSAGE: %s\n",
-                        get_usb_statmsg(ret));
-                return ret;
+                        get_usb_rcmsg(rc));
+                return rc;
         }
 
-        /* submitted successfully */
-        update_basstate(ucs, 0, BS_ATREADY);
-
-        /* start timeout if necessary */
-        if (!(atomic_read(&ucs->basstate) & BS_ATTIMER)) {
+        /* submitted successfully, start timeout if necessary */
+        if (!(update_basstate(ucs, BS_ATTIMER, BS_ATREADY) & BS_ATTIMER)) {
                 gig_dbg(DEBUG_OUTPUT, "setting ATREADY timeout of %d/10 secs",
                         ATRDY_TIMEOUT);
                 ucs->timer_atrdy.expires = jiffies + ATRDY_TIMEOUT * HZ / 10;
                 ucs->timer_atrdy.data = (unsigned long) cs;
                 ucs->timer_atrdy.function = atrdy_timeout;
                 add_timer(&ucs->timer_atrdy);
-                update_basstate(ucs, BS_ATTIMER, 0);
         }
         return 0;
 }
@@ -1702,7 +1741,6 @@ static int start_cbsend(struct cardstate *cs)
                 gig_dbg(DEBUG_TRANSCMD|DEBUG_LOCKCMD, "AT channel not open");
                 rc = req_submit(cs->bcs, HD_OPEN_ATCHANNEL, 0, BAS_TIMEOUT);
                 if (rc < 0) {
-                        dev_err(cs->dev, "could not open AT channel\n");
                         /* flush command queue */
                         spin_lock_irqsave(&cs->cmdlock, flags);
                         while (cs->cmdbuf != NULL)
@@ -1786,8 +1824,14 @@ static int gigaset_write_cmd(struct cardstate *cs,
         cs->lastcmdbuf = cb;
         spin_unlock_irqrestore(&cs->cmdlock, flags);
 
+        spin_lock_irqsave(&cs->lock, flags);
+        if (unlikely(!cs->connected)) {
+                spin_unlock_irqrestore(&cs->lock, flags);
+                gig_dbg(DEBUG_USBREQ, "%s: not connected", __func__);
+                return -ENODEV;
+        }
         status = start_cbsend(cs);
-
+        spin_unlock_irqrestore(&cs->lock, flags);
         return status < 0 ? status : len;
 }
 
@@ -1849,12 +1893,32 @@ static int gigaset_brkchars(struct cardstate *cs, const unsigned char buf[6])
  */
 static int gigaset_freebcshw(struct bc_state *bcs)
 {
-        if (!bcs->hw.bas)
+        struct bas_bc_state *ubc = bcs->hw.bas;
+        int i;
+
+        if (!ubc)
                 return 0;
 
-        if (bcs->hw.bas->isooutbuf)
-                kfree(bcs->hw.bas->isooutbuf);
-        kfree(bcs->hw.bas);
+        /* kill URBs and tasklets before freeing - better safe than sorry */
+        atomic_set(&ubc->running, 0);
+        for (i = 0; i < BAS_OUTURBS; ++i)
+                if (ubc->isoouturbs[i].urb) {
+                        gig_dbg(DEBUG_INIT, "%s: killing iso out URB %d",
+                                __func__, i);
+                        usb_kill_urb(ubc->isoouturbs[i].urb);
+                        usb_free_urb(ubc->isoouturbs[i].urb);
+                }
+        for (i = 0; i < BAS_INURBS; ++i)
+                if (ubc->isoinurbs[i]) {
+                        gig_dbg(DEBUG_INIT, "%s: killing iso in URB %d",
+                                __func__, i);
+                        usb_kill_urb(ubc->isoinurbs[i]);
+                        usb_free_urb(ubc->isoinurbs[i]);
+                }
+        tasklet_kill(&ubc->sent_tasklet);
+        tasklet_kill(&ubc->rcvd_tasklet);
+        kfree(ubc->isooutbuf);
+        kfree(ubc);
         bcs->hw.bas = NULL;
         return 1;
 }
@@ -1931,13 +1995,9 @@ static void gigaset_reinitbcshw(struct bc_state *bcs)
 
 static void gigaset_freecshw(struct cardstate *cs)
 {
-        struct bas_cardstate *ucs = cs->hw.bas;
-
-        del_timer(&ucs->timer_ctrl);
-        del_timer(&ucs->timer_atrdy);
-        del_timer(&ucs->timer_cmd_in);
-
+        /* timers, URBs and rcvbuf are disposed of in disconnect */
         kfree(cs->hw.bas);
+        cs->hw.bas = NULL;
 }
 
 static int gigaset_initcshw(struct cardstate *cs)
@@ -2041,23 +2101,13 @@ static int gigaset_probe(struct usb_interface *interface,
         struct bas_bc_state *ubc;
         struct usb_endpoint_descriptor *endpoint;
         int i, j;
-        int ret;
+        int rc;
 
         gig_dbg(DEBUG_ANY,
                 "%s: Check if device matches .. (Vendor: 0x%x, Product: 0x%x)",
                 __func__, le16_to_cpu(udev->descriptor.idVendor),
                 le16_to_cpu(udev->descriptor.idProduct));
 
-        /* See if the device offered us matches what we can accept */
-        if ((le16_to_cpu(udev->descriptor.idVendor)  != USB_GIGA_VENDOR_ID) ||
-            (le16_to_cpu(udev->descriptor.idProduct) != USB_GIGA_PRODUCT_ID &&
-             le16_to_cpu(udev->descriptor.idProduct) != USB_4175_PRODUCT_ID &&
-             le16_to_cpu(udev->descriptor.idProduct) != USB_SX303_PRODUCT_ID &&
-             le16_to_cpu(udev->descriptor.idProduct) != USB_SX353_PRODUCT_ID)) {
-                gig_dbg(DEBUG_ANY, "%s: unmatched ID - exiting", __func__);
-                return -ENODEV;
-        }
-
         /* set required alternate setting */
         hostif = interface->cur_altsetting;
         if (hostif->desc.bAlternateSetting != 3) {
@@ -2105,45 +2155,22 @@ static int gigaset_probe(struct usb_interface *interface,
          * - three for the different uses of the default control pipe
          * - three for each isochronous pipe
          */
-        ucs->urb_int_in = usb_alloc_urb(0, SLAB_KERNEL);
-        if (!ucs->urb_int_in) {
-                dev_err(cs->dev, "no free urbs available\n");
-                goto error;
-        }
-        ucs->urb_cmd_in = usb_alloc_urb(0, SLAB_KERNEL);
-        if (!ucs->urb_cmd_in) {
-                dev_err(cs->dev, "no free urbs available\n");
-                goto error;
-        }
-        ucs->urb_cmd_out = usb_alloc_urb(0, SLAB_KERNEL);
-        if (!ucs->urb_cmd_out) {
-                dev_err(cs->dev, "no free urbs available\n");
-                goto error;
-        }
-        ucs->urb_ctrl = usb_alloc_urb(0, SLAB_KERNEL);
-        if (!ucs->urb_ctrl) {
-                dev_err(cs->dev, "no free urbs available\n");
-                goto error;
-        }
+        if (!(ucs->urb_int_in = usb_alloc_urb(0, SLAB_KERNEL)) ||
+            !(ucs->urb_cmd_in = usb_alloc_urb(0, SLAB_KERNEL)) ||
+            !(ucs->urb_cmd_out = usb_alloc_urb(0, SLAB_KERNEL)) ||
+            !(ucs->urb_ctrl = usb_alloc_urb(0, SLAB_KERNEL)))
+                goto allocerr;
 
         for (j = 0; j < 2; ++j) {
                 ubc = cs->bcs[j].hw.bas;
-                for (i = 0; i < BAS_OUTURBS; ++i) {
-                        ubc->isoouturbs[i].urb =
-                                usb_alloc_urb(BAS_NUMFRAMES, SLAB_KERNEL);
-                        if (!ubc->isoouturbs[i].urb) {
-                                dev_err(cs->dev, "no free urbs available\n");
-                                goto error;
-                        }
-                }
-                for (i = 0; i < BAS_INURBS; ++i) {
-                        ubc->isoinurbs[i] =
-                                usb_alloc_urb(BAS_NUMFRAMES, SLAB_KERNEL);
-                        if (!ubc->isoinurbs[i]) {
-                                dev_err(cs->dev, "no free urbs available\n");
-                                goto error;
-                        }
-                }
+                for (i = 0; i < BAS_OUTURBS; ++i)
+                        if (!(ubc->isoouturbs[i].urb =
+                              usb_alloc_urb(BAS_NUMFRAMES, SLAB_KERNEL)))
+                                goto allocerr;
+                for (i = 0; i < BAS_INURBS; ++i)
+                        if (!(ubc->isoinurbs[i] =
+                              usb_alloc_urb(BAS_NUMFRAMES, SLAB_KERNEL)))
+                                goto allocerr;
         }
 
         ucs->rcvbuf = NULL;
@@ -2156,15 +2183,14 @@ static int gigaset_probe(struct usb_interface *interface,
                                         (endpoint->bEndpointAddress) & 0x0f),
                          ucs->int_in_buf, 3, read_int_callback, cs,
                          endpoint->bInterval);
-        ret = usb_submit_urb(ucs->urb_int_in, SLAB_KERNEL);
-        if (ret) {
+        if ((rc = usb_submit_urb(ucs->urb_int_in, SLAB_KERNEL)) != 0) {
                 dev_err(cs->dev, "could not submit interrupt URB: %s\n",
-                        get_usb_statmsg(ret));
+                        get_usb_rcmsg(rc));
                 goto error;
         }
 
         /* tell the device that the driver is ready */
-        if ((ret = req_submit(cs->bcs, HD_DEVICE_INIT_ACK, 0, 0)) != 0)
+        if ((rc = req_submit(cs->bcs, HD_DEVICE_INIT_ACK, 0, 0)) != 0)
                 goto error;
 
         /* tell common part that the device is ready */
@@ -2179,6 +2205,8 @@ static int gigaset_probe(struct usb_interface *interface,
 
         return 0;
 
+allocerr:
+        dev_err(cs->dev, "could not allocate URBs\n");
 error:
         freeurbs(cs);
         usb_set_intfdata(interface, NULL);
@@ -2193,19 +2221,34 @@ static void gigaset_disconnect(struct usb_interface *interface)
 {
         struct cardstate *cs;
         struct bas_cardstate *ucs;
+        int j;
 
         cs = usb_get_intfdata(interface);
 
         ucs = cs->hw.bas;
 
         dev_info(cs->dev, "disconnecting Gigaset base\n");
+
+        /* mark base as not ready, all channels disconnected */
+        atomic_set(&ucs->basstate, 0);
+
+        /* tell LL all channels are down */
+        //FIXME shouldn't gigaset_stop() do this?
+        for (j = 0; j < 2; ++j)
+                gigaset_bchannel_down(cs->bcs + j);
+
+        /* stop driver (common part) */
         gigaset_stop(cs);
+
+        /* stop timers and URBs, free ressources */
+        del_timer_sync(&ucs->timer_ctrl);
+        del_timer_sync(&ucs->timer_atrdy);
+        del_timer_sync(&ucs->timer_cmd_in);
         freeurbs(cs);
         usb_set_intfdata(interface, NULL);
         kfree(ucs->rcvbuf);
         ucs->rcvbuf = NULL;
         ucs->rcvbuf_size = 0;
-        atomic_set(&ucs->basstate, 0);
         usb_put_dev(ucs->udev);
         ucs->interface = NULL;
         ucs->udev = NULL;
@@ -2277,6 +2320,8 @@ error:	if (cardstate)
  */
 static void __exit bas_gigaset_exit(void)
 {
+        struct bas_cardstate *ucs = cardstate->hw.bas;
+
         gigaset_blockdriver(driver); /* => probe will fail
                                       * => no gigaset_start any more
                                       */
@@ -2284,14 +2329,26 @@ static void __exit bas_gigaset_exit(void)
         gigaset_shutdown(cardstate);
         /* from now on, no isdn callback should be possible */
 
-        if (atomic_read(&cardstate->hw.bas->basstate) & BS_ATOPEN) {
-                gig_dbg(DEBUG_ANY, "closing AT channel");
-                if (req_submit(cardstate->bcs,
-                               HD_CLOSE_ATCHANNEL, 0, BAS_TIMEOUT) >= 0) {
-                        /* successfully submitted */
-                        //FIXME wait for completion?
-                }
+        /* close all still open channels */
+        if (atomic_read(&ucs->basstate) & BS_B1OPEN) {
+                gig_dbg(DEBUG_INIT, "closing B1 channel");
+                usb_control_msg(ucs->udev, usb_sndctrlpipe(ucs->udev, 0),
+                                HD_CLOSE_B1CHANNEL, OUT_VENDOR_REQ, 0, 0,
+                                NULL, 0, BAS_TIMEOUT);
+        }
+        if (atomic_read(&ucs->basstate) & BS_B2OPEN) {
+                gig_dbg(DEBUG_INIT, "closing B2 channel");
+                usb_control_msg(ucs->udev, usb_sndctrlpipe(ucs->udev, 0),
+                                HD_CLOSE_B2CHANNEL, OUT_VENDOR_REQ, 0, 0,
+                                NULL, 0, BAS_TIMEOUT);
+        }
+        if (atomic_read(&ucs->basstate) & BS_ATOPEN) {
+                gig_dbg(DEBUG_INIT, "closing AT channel");
+                usb_control_msg(ucs->udev, usb_sndctrlpipe(ucs->udev, 0),
+                                HD_CLOSE_ATCHANNEL, OUT_VENDOR_REQ, 0, 0,
+                                NULL, 0, BAS_TIMEOUT);
         }
+        atomic_set(&ucs->basstate, 0);
 
         /* deregister this driver with the USB subsystem */
         usb_deregister(&gigaset_usb_driver);
diff --git a/drivers/isdn/gigaset/common.c b/drivers/isdn/gigaset/common.c
index 749b3da1236e..e55767b2ccd3 100644
--- a/drivers/isdn/gigaset/common.c
+++ b/drivers/isdn/gigaset/common.c
@@ -781,8 +781,7 @@ error:	if (cs)
 }
 EXPORT_SYMBOL_GPL(gigaset_initcs);
 
-/* ReInitialize the b-channel structure */
-/* e.g. called on hangup, disconnect */
+/* ReInitialize the b-channel structure on hangup */
 void gigaset_bcs_reinit(struct bc_state *bcs)
 {
         struct sk_buff *skb;
diff --git a/drivers/isdn/gigaset/ev-layer.c b/drivers/isdn/gigaset/ev-layer.c
index 1ba3424a286b..18e05c09b71c 100644
--- a/drivers/isdn/gigaset/ev-layer.c
+++ b/drivers/isdn/gigaset/ev-layer.c
@@ -373,6 +373,9 @@ struct reply_t gigaset_tab_cid_m10x[] = /* for M10x */
 
         {EV_TIMEOUT,  750,750, -1,                  0, 0, {ACT_CONNTIMEOUT}},
 
+        /* B channel closed (general case) */
+        {EV_BC_CLOSED, -1, -1, -1,                 -1,-1, {ACT_NOTIFY_BC_DOWN}}, //FIXME
+
         /* misc. */
         {EV_PROTO_L2,  -1, -1, -1,                 -1,-1, {ACT_PROTO_L2}}, //FIXME
 
diff --git a/drivers/isdn/gigaset/gigaset.h b/drivers/isdn/gigaset/gigaset.h
index 9d21ba8757b0..22b9693f7c0a 100644
--- a/drivers/isdn/gigaset/gigaset.h
+++ b/drivers/isdn/gigaset/gigaset.h
@@ -75,7 +75,7 @@ extern int gigaset_debuglevel;	/* "needs" cast to (enum debuglevel) */
  * e.g. 'insmod usb_gigaset.o debug=0x2c' will set DEBUG_OPEN, DEBUG_CMD and
  * DEBUG_INTR.
  */
-enum debuglevel { /* up to 24 bits (atomic_t) */
+enum debuglevel {
         DEBUG_REG         = 0x0002, /* serial port I/O register operations */
         DEBUG_OPEN        = 0x0004, /* open/close serial port */
         DEBUG_INTR        = 0x0008, /* interrupt processing */
@@ -141,7 +141,7 @@ enum debuglevel { /* up to 24 bits (atomic_t) */
                         printk(KERN_DEBUG KBUILD_MODNAME ": " format "\n", \
                                ## arg); \
         } while (0)
-#define DEBUG_DEFAULT (DEBUG_INIT | DEBUG_TRANSCMD | DEBUG_CMD | DEBUG_USBREQ)
+#define DEBUG_DEFAULT (DEBUG_TRANSCMD | DEBUG_CMD | DEBUG_USBREQ)
 
 #else
 
@@ -627,8 +627,7 @@ struct gigaset_ops {
         /* Called by gigaset_freecs() for freeing bcs->hw.xxx */
         int (*freebcshw)(struct bc_state *bcs);
 
-        /* Called by gigaset_stop() or gigaset_bchannel_down() for resetting
-           bcs->hw.xxx */
+        /* Called by gigaset_bchannel_down() for resetting bcs->hw.xxx */
         void (*reinitbcshw)(struct bc_state *bcs);
 
         /* Called by gigaset_initcs() for setting up cs->hw.xxx */
diff --git a/drivers/isdn/gigaset/i4l.c b/drivers/isdn/gigaset/i4l.c
index 0815dbfb8291..1654fa413575 100644
--- a/drivers/isdn/gigaset/i4l.c
+++ b/drivers/isdn/gigaset/i4l.c
@@ -73,7 +73,7 @@ static int writebuf_from_LL(int driverID, int channel, int ack,
                 len, skblen, (unsigned) skb->head[0], (unsigned) skb->head[1]);
 
         /* pass to device-specific module */
-        return cs->ops->send_skb(bcs, skb); //FIXME cs->ops->send_skb() must handle !cs->connected correctly
+        return cs->ops->send_skb(bcs, skb);
 }
 
 void gigaset_skb_sent(struct bc_state *bcs, struct sk_buff *skb)
diff --git a/drivers/isdn/gigaset/isocdata.c b/drivers/isdn/gigaset/isocdata.c
index 45f017ed6e8c..8667daaa1a82 100644
--- a/drivers/isdn/gigaset/isocdata.c
+++ b/drivers/isdn/gigaset/isocdata.c
@@ -992,14 +992,18 @@ int gigaset_isoc_send_skb(struct bc_state *bcs, struct sk_buff *skb)
         int len = skb->len;
         unsigned long flags;
 
+        spin_lock_irqsave(&bcs->cs->lock, flags);
+        if (!bcs->cs->connected) {
+                spin_unlock_irqrestore(&bcs->cs->lock, flags);
+                return -ENODEV;
+        }
+
         skb_queue_tail(&bcs->squeue, skb);
         gig_dbg(DEBUG_ISO, "%s: skb queued, qlen=%d",
                 __func__, skb_queue_len(&bcs->squeue));
 
         /* tasklet submits URB if necessary */
-        spin_lock_irqsave(&bcs->cs->lock, flags);
-        if (bcs->cs->connected)
-                tasklet_schedule(&bcs->hw.bas->sent_tasklet);
+        tasklet_schedule(&bcs->hw.bas->sent_tasklet);
         spin_unlock_irqrestore(&bcs->cs->lock, flags);
 
         return len;     /* ok so far */