[PATCH] isdn4linux: Siemens Gigaset drivers: make some variables non-atomic

With Hansjoerg Lipp <hjlipp@web.de>

Replace some atomic_t variables in the Gigaset drivers by non-atomic ones,
using spinlocks instead to assure atomicity, as proposed in discussions on the
linux-kernel mailing list.

Signed-off-by: Hansjoerg Lipp <hjlipp@web.de>
Signed-off-by: Tilman Schmidt <tilman@imap.cc>
Cc: Karsten Keil <kkeil@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

10 files changed, 211 insertions, 154 deletions

diff --git a/drivers/isdn/gigaset/asyncdata.c b/drivers/isdn/gigaset/asyncdata.c
index ce60f6521b96..ce3cd77094b3 100644
--- a/drivers/isdn/gigaset/asyncdata.c
+++ b/drivers/isdn/gigaset/asyncdata.c
@@ -566,19 +566,22 @@ static struct sk_buff *iraw_encode(struct sk_buff *skb, int head, int tail)
 int gigaset_m10x_send_skb(struct bc_state *bcs, struct sk_buff *skb)
 {
         unsigned len = skb->len;
+        unsigned long flags;
 
         if (bcs->proto2 == ISDN_PROTO_L2_HDLC)
                 skb = HDLC_Encode(skb, HW_HDR_LEN, 0);
         else
                 skb = iraw_encode(skb, HW_HDR_LEN, 0);
         if (!skb) {
-                dev_err(bcs->cs->dev,
-                        "unable to allocate memory for encoding!\n");
+                err("unable to allocate memory for encoding!\n");
                 return -ENOMEM;
         }
 
         skb_queue_tail(&bcs->squeue, skb);
-        tasklet_schedule(&bcs->cs->write_tasklet);
+        spin_lock_irqsave(&bcs->cs->lock, flags);
+        if (bcs->cs->connected)
+                tasklet_schedule(&bcs->cs->write_tasklet);
+        spin_unlock_irqrestore(&bcs->cs->lock, flags);
 
         return len;     /* ok so far */
 }
diff --git a/drivers/isdn/gigaset/bas-gigaset.c b/drivers/isdn/gigaset/bas-gigaset.c
index fa37db68c962..f86ed6af3aa2 100644
--- a/drivers/isdn/gigaset/bas-gigaset.c
+++ b/drivers/isdn/gigaset/bas-gigaset.c
@@ -367,7 +367,7 @@ static void cmd_in_timeout(unsigned long data)
         unsigned long flags;
 
         spin_lock_irqsave(&cs->lock, flags);
-        if (unlikely(!atomic_read(&cs->connected))) {
+        if (unlikely(!cs->connected)) {
                 gig_dbg(DEBUG_USBREQ, "%s: disconnected", __func__);
                 spin_unlock_irqrestore(&cs->lock, flags);
                 return;
@@ -475,11 +475,6 @@ static void read_int_callback(struct urb *urb, struct pt_regs *regs)
         unsigned l;
         int channel;
 
-        if (unlikely(!atomic_read(&cs->connected))) {
-                warn("%s: disconnected", __func__);
-                return;
-        }
-
         switch (urb->status) {
         case 0:                 /* success */
                 break;
@@ -603,7 +598,9 @@ static void read_int_callback(struct urb *urb, struct pt_regs *regs)
         check_pending(ucs);
 
 resubmit:
-        status = usb_submit_urb(urb, SLAB_ATOMIC);
+        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)) {
                 dev_err(cs->dev, "could not resubmit interrupt URB: %s\n",
                         get_usb_statmsg(status));
@@ -628,7 +625,7 @@ static void read_ctrl_callback(struct urb *urb, struct pt_regs *regs)
         unsigned long flags;
 
         spin_lock_irqsave(&cs->lock, flags);
-        if (unlikely(!atomic_read(&cs->connected))) {
+        if (unlikely(!cs->connected)) {
                 warn("%s: disconnected", __func__);
                 spin_unlock_irqrestore(&cs->lock, flags);
                 return;
@@ -949,6 +946,7 @@ 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;
@@ -995,7 +993,11 @@ static int submit_iso_write_urb(struct isow_urbctx_t *ucx)
                 ifd->actual_length = 0;
         }
         if ((urb->number_of_packets = nframe) > 0) {
-                if ((rc = usb_submit_urb(urb, SLAB_ATOMIC)) != 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 (rc) {
                         dev_err(ucx->bcs->cs->dev,
                                 "could not submit isochronous write URB: %s\n",
                                 get_usb_statmsg(rc));
@@ -1029,11 +1031,6 @@ static void write_iso_tasklet(unsigned long data)
 
         /* loop while completed URBs arrive in time */
         for (;;) {
-                if (unlikely(!atomic_read(&cs->connected))) {
-                        warn("%s: disconnected", __func__);
-                        return;
-                }
-
                 if (unlikely(!(atomic_read(&ubc->running)))) {
                         gig_dbg(DEBUG_ISO, "%s: not running", __func__);
                         return;
@@ -1190,11 +1187,6 @@ static void read_iso_tasklet(unsigned long data)
 
         /* loop while more completed URBs arrive in the meantime */
         for (;;) {
-                if (unlikely(!atomic_read(&cs->connected))) {
-                        warn("%s: disconnected", __func__);
-                        return;
-                }
-
                 /* retrieve URB */
                 spin_lock_irqsave(&ubc->isoinlock, flags);
                 if (!(urb = ubc->isoindone)) {
@@ -1298,7 +1290,10 @@ 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;
-                if ((rc = usb_submit_urb(urb, SLAB_ATOMIC)) != 0) {
+                spin_lock_irqsave(&cs->lock, flags);
+                rc = cs->connected ? usb_submit_urb(urb, SLAB_ATOMIC) : -ENODEV;
+                spin_unlock_irqrestore(&cs->lock, flags);
+                if (rc) {
                         dev_err(cs->dev,
                                 "could not resubmit isochronous read URB: %s\n",
                                 get_usb_statmsg(rc));
@@ -1639,6 +1634,7 @@ static void atrdy_timeout(unsigned long data)
 static int atwrite_submit(struct cardstate *cs, unsigned char *buf, int len)
 {
         struct bas_cardstate *ucs = cs->hw.bas;
+        unsigned long flags;
         int ret;
 
         gig_dbg(DEBUG_USBREQ, "-------> HD_WRITE_ATMESSAGE (%d)", len);
@@ -1659,7 +1655,11 @@ static int atwrite_submit(struct cardstate *cs, unsigned char *buf, int len)
                              (unsigned char*) &ucs->dr_cmd_out, buf, len,
                              write_command_callback, cs);
 
-        if ((ret = usb_submit_urb(ucs->urb_cmd_out, SLAB_ATOMIC)) != 0) {
+        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) {
                 dev_err(cs->dev, "could not submit HD_WRITE_ATMESSAGE: %s\n",
                         get_usb_statmsg(ret));
                 return ret;
@@ -1758,11 +1758,6 @@ static int gigaset_write_cmd(struct cardstate *cs,
                              DEBUG_TRANSCMD : DEBUG_LOCKCMD,
                            "CMD Transmit", len, buf);
 
-        if (unlikely(!atomic_read(&cs->connected))) {
-                err("%s: disconnected", __func__);
-                return -ENODEV;
-        }
-
         if (len <= 0)
                 return 0;                       /* nothing to do */
 
@@ -2186,6 +2181,7 @@ static int gigaset_probe(struct usb_interface *interface,
 
 error:
         freeurbs(cs);
+        usb_set_intfdata(interface, NULL);
         gigaset_unassign(cs);
         return -ENODEV;
 }
diff --git a/drivers/isdn/gigaset/common.c b/drivers/isdn/gigaset/common.c
index f8e5759c636c..d00acddd6213 100644
--- a/drivers/isdn/gigaset/common.c
+++ b/drivers/isdn/gigaset/common.c
@@ -129,11 +129,6 @@ int gigaset_enterconfigmode(struct cardstate *cs)
 {
         int i, r;
 
-        if (!atomic_read(&cs->connected)) {
-                err("not connected!");
-                return -1;
-        }
-
         cs->control_state = TIOCM_RTS; //FIXME
 
         r = setflags(cs, TIOCM_DTR, 200);
@@ -176,7 +171,7 @@ static int test_timeout(struct at_state_t *at_state)
         }
 
         if (!gigaset_add_event(at_state->cs, at_state, EV_TIMEOUT, NULL,
-                               atomic_read(&at_state->timer_index), NULL)) {
+                               at_state->timer_index, NULL)) {
                 //FIXME what should we do?
         }
 
@@ -204,7 +199,7 @@ static void timer_tick(unsigned long data)
                 if (test_timeout(at_state))
                         timeout = 1;
 
-        if (atomic_read(&cs->running)) {
+        if (cs->running) {
                 mod_timer(&cs->timer, jiffies + msecs_to_jiffies(GIG_TICK));
                 if (timeout) {
                         gig_dbg(DEBUG_CMD, "scheduling timeout");
@@ -298,20 +293,22 @@ static void clear_events(struct cardstate *cs)
 {
         struct event_t *ev;
         unsigned head, tail;
+        unsigned long flags;
 
-        /* no locking needed (no reader/writer allowed) */
+        spin_lock_irqsave(&cs->ev_lock, flags);
 
-        head = atomic_read(&cs->ev_head);
-        tail = atomic_read(&cs->ev_tail);
+        head = cs->ev_head;
+        tail = cs->ev_tail;
 
         while (tail != head) {
                 ev = cs->events + head;
                 kfree(ev->ptr);
-
                 head = (head + 1) % MAX_EVENTS;
         }
 
-        atomic_set(&cs->ev_head, tail);
+        cs->ev_head = tail;
+
+        spin_unlock_irqrestore(&cs->ev_lock, flags);
 }
 
 struct event_t *gigaset_add_event(struct cardstate *cs,
@@ -324,9 +321,9 @@ struct event_t *gigaset_add_event(struct cardstate *cs,
 
         spin_lock_irqsave(&cs->ev_lock, flags);
 
-        tail = atomic_read(&cs->ev_tail);
+        tail = cs->ev_tail;
         next = (tail + 1) % MAX_EVENTS;
-        if (unlikely(next == atomic_read(&cs->ev_head)))
+        if (unlikely(next == cs->ev_head))
                 err("event queue full");
         else {
                 event = cs->events + tail;
@@ -336,7 +333,7 @@ struct event_t *gigaset_add_event(struct cardstate *cs,
                 event->ptr = ptr;
                 event->arg = arg;
                 event->parameter = parameter;
-                atomic_set(&cs->ev_tail, next);
+                cs->ev_tail = next;
         }
 
         spin_unlock_irqrestore(&cs->ev_lock, flags);
@@ -454,7 +451,7 @@ void gigaset_freecs(struct cardstate *cs)
                 goto f_bcs;
 
         spin_lock_irqsave(&cs->lock, flags);
-        atomic_set(&cs->running, 0);
+        cs->running = 0;
         spin_unlock_irqrestore(&cs->lock, flags); /* event handler and timer are
                                                      not rescheduled below */
 
@@ -513,8 +510,8 @@ void gigaset_at_init(struct at_state_t *at_state, struct bc_state *bcs,
         at_state->pending_commands = 0;
         at_state->timer_expires = 0;
         at_state->timer_active = 0;
-        atomic_set(&at_state->timer_index, 0);
-        atomic_set(&at_state->seq_index, 0);
+        at_state->timer_index = 0;
+        at_state->seq_index = 0;
         at_state->ConState = 0;
         for (i = 0; i < STR_NUM; ++i)
                 at_state->str_var[i] = NULL;
@@ -665,6 +662,7 @@ struct cardstate *gigaset_initcs(struct gigaset_driver *drv, int channels,
                                  int cidmode, const char *modulename)
 {
         struct cardstate *cs = NULL;
+        unsigned long flags;
         int i;
 
         gig_dbg(DEBUG_INIT, "allocating cs");
@@ -685,11 +683,11 @@ struct cardstate *gigaset_initcs(struct gigaset_driver *drv, int channels,
         cs->onechannel = onechannel;
         cs->ignoreframes = ignoreframes;
         INIT_LIST_HEAD(&cs->temp_at_states);
-        atomic_set(&cs->running, 0);
+        cs->running = 0;
         init_timer(&cs->timer); /* clear next & prev */
         spin_lock_init(&cs->ev_lock);
-        atomic_set(&cs->ev_tail, 0);
-        atomic_set(&cs->ev_head, 0);
+        cs->ev_tail = 0;
+        cs->ev_head = 0;
         mutex_init(&cs->mutex);
         mutex_lock(&cs->mutex);
 
@@ -701,7 +699,7 @@ struct cardstate *gigaset_initcs(struct gigaset_driver *drv, int channels,
         cs->open_count = 0;
         cs->dev = NULL;
         cs->tty = NULL;
-        atomic_set(&cs->cidmode, cidmode != 0);
+        cs->cidmode = cidmode != 0;
 
         //if(onechannel) { //FIXME
                 cs->tabnocid = gigaset_tab_nocid_m10x;
@@ -737,7 +735,8 @@ struct cardstate *gigaset_initcs(struct gigaset_driver *drv, int channels,
         } else
                 gigaset_inbuf_init(cs->inbuf, NULL,    cs, INS_command);
 
-        atomic_set(&cs->connected, 0);
+        cs->connected = 0;
+        cs->isdn_up = 0;
 
         gig_dbg(DEBUG_INIT, "setting up cmdbuf");
         cs->cmdbuf = cs->lastcmdbuf = NULL;
@@ -761,7 +760,9 @@ struct cardstate *gigaset_initcs(struct gigaset_driver *drv, int channels,
 
         gigaset_if_init(cs);
 
-        atomic_set(&cs->running, 1);
+        spin_lock_irqsave(&cs->lock, flags);
+        cs->running = 1;
+        spin_unlock_irqrestore(&cs->lock, flags);
         setup_timer(&cs->timer, timer_tick, (unsigned long) cs);
         cs->timer.expires = jiffies + msecs_to_jiffies(GIG_TICK);
         /* FIXME: can jiffies increase too much until the timer is added?
@@ -871,10 +872,14 @@ static void cleanup_cs(struct cardstate *cs)
 
 int gigaset_start(struct cardstate *cs)
 {
+        unsigned long flags;
+
         if (mutex_lock_interruptible(&cs->mutex))
                 return 0;
 
-        atomic_set(&cs->connected, 1);
+        spin_lock_irqsave(&cs->lock, flags);
+        cs->connected = 1;
+        spin_unlock_irqrestore(&cs->lock, flags);
 
         if (atomic_read(&cs->mstate) != MS_LOCKED) {
                 cs->ops->set_modem_ctrl(cs, 0, TIOCM_DTR|TIOCM_RTS);
@@ -950,11 +955,6 @@ void gigaset_stop(struct cardstate *cs)
 {
         mutex_lock(&cs->mutex);
 
-        /* clear device sysfs */
-        gigaset_free_dev_sysfs(cs);
-
-        atomic_set(&cs->connected, 0);
-
         cs->waiting = 1;
 
         if (!gigaset_add_event(cs, &cs->at_state, EV_STOP, NULL, 0, NULL)) {
@@ -970,8 +970,8 @@ void gigaset_stop(struct cardstate *cs)
                 //FIXME
         }
 
-        /* Tell the LL that the device is not available .. */
-        gigaset_i4l_cmd(cs, ISDN_STAT_STOP); // FIXME move to event layer?
+        /* clear device sysfs */
+        gigaset_free_dev_sysfs(cs);
 
         cleanup_cs(cs);
 
diff --git a/drivers/isdn/gigaset/ev-layer.c b/drivers/isdn/gigaset/ev-layer.c
index 2e826d051c85..1ba3424a286b 100644
--- a/drivers/isdn/gigaset/ev-layer.c
+++ b/drivers/isdn/gigaset/ev-layer.c
@@ -482,14 +482,6 @@ static int isdn_gethex(char *p)
         return v;
 }
 
-static inline void new_index(atomic_t *index, int max)
-{
-        if (atomic_read(index) == max)  //FIXME race?
-                atomic_set(index, 0);
-        else
-                atomic_inc(index);
-}
-
 /* retrieve CID from parsed response
  * returns 0 if no CID, -1 if invalid CID, or CID value 1..65535
  */
@@ -581,8 +573,8 @@ void gigaset_handle_modem_response(struct cardstate *cs)
         }
 
         spin_lock_irqsave(&cs->ev_lock, flags);
-        head = atomic_read(&cs->ev_head);
-        tail = atomic_read(&cs->ev_tail);
+        head = cs->ev_head;
+        tail = cs->ev_tail;
 
         abort = 1;
         curarg = 0;
@@ -715,7 +707,7 @@ void gigaset_handle_modem_response(struct cardstate *cs)
                         break;
         }
 
-        atomic_set(&cs->ev_tail, tail);
+        cs->ev_tail = tail;
         spin_unlock_irqrestore(&cs->ev_lock, flags);
 
         if (curarg != params)
@@ -734,14 +726,16 @@ static void disconnect(struct at_state_t **at_state_p)
         struct bc_state *bcs = (*at_state_p)->bcs;
         struct cardstate *cs = (*at_state_p)->cs;
 
-        new_index(&(*at_state_p)->seq_index, MAX_SEQ_INDEX);
+        spin_lock_irqsave(&cs->lock, flags);
+        ++(*at_state_p)->seq_index;
 
         /* revert to selected idle mode */
-        if (!atomic_read(&cs->cidmode)) {
+        if (!cs->cidmode) {
                 cs->at_state.pending_commands |= PC_UMMODE;
                 atomic_set(&cs->commands_pending, 1); //FIXME
                 gig_dbg(DEBUG_CMD, "Scheduling PC_UMMODE");
         }
+        spin_unlock_irqrestore(&cs->lock, flags);
 
         if (bcs) {
                 /* B channel assigned: invoke hardware specific handler */
@@ -933,17 +927,21 @@ static void bchannel_up(struct bc_state *bcs)
         gigaset_i4l_channel_cmd(bcs, ISDN_STAT_BCONN);
 }
 
-static void start_dial(struct at_state_t *at_state, void *data, int seq_index)
+static void start_dial(struct at_state_t *at_state, void *data, unsigned seq_index)
 {
         struct bc_state *bcs = at_state->bcs;
         struct cardstate *cs = at_state->cs;
         int retval;
+        unsigned long flags;
 
         bcs->chstate |= CHS_NOTIFY_LL;
-        //atomic_set(&bcs->status, BCS_INIT);
 
-        if (atomic_read(&at_state->seq_index) != seq_index)
+        spin_lock_irqsave(&cs->lock, flags);
+        if (at_state->seq_index != seq_index) {
+                spin_unlock_irqrestore(&cs->lock, flags);
                 goto error;
+        }
+        spin_unlock_irqrestore(&cs->lock, flags);
 
         retval = gigaset_isdn_setup_dial(at_state, data);
         if (retval != 0)
@@ -988,6 +986,7 @@ static void do_start(struct cardstate *cs)
         if (atomic_read(&cs->mstate) != MS_LOCKED)
                 schedule_init(cs, MS_INIT);
 
+        cs->isdn_up = 1;
         gigaset_i4l_cmd(cs, ISDN_STAT_RUN);
                                         // FIXME: not in locked mode
                                         // FIXME 2: only after init sequence
@@ -1003,6 +1002,12 @@ static void finish_shutdown(struct cardstate *cs)
                 atomic_set(&cs->mode, M_UNKNOWN);
         }
 
+        /* Tell the LL that the device is not available .. */
+        if (cs->isdn_up) {
+                cs->isdn_up = 0;
+                gigaset_i4l_cmd(cs, ISDN_STAT_STOP);
+        }
+
         /* The rest is done by cleanup_cs () in user mode. */
 
         cs->cmd_result = -ENODEV;
@@ -1025,6 +1030,12 @@ static void do_shutdown(struct cardstate *cs)
 
 static void do_stop(struct cardstate *cs)
 {
+        unsigned long flags;
+
+        spin_lock_irqsave(&cs->lock, flags);
+        cs->connected = 0;
+        spin_unlock_irqrestore(&cs->lock, flags);
+
         do_shutdown(cs);
 }
 
@@ -1153,7 +1164,7 @@ static int do_unlock(struct cardstate *cs)
         atomic_set(&cs->mstate, MS_UNINITIALIZED);
         atomic_set(&cs->mode, M_UNKNOWN);
         gigaset_free_channels(cs);
-        if (atomic_read(&cs->connected))
+        if (cs->connected)
                 schedule_init(cs, MS_INIT);
 
         return 0;
@@ -1185,11 +1196,14 @@ static void do_action(int action, struct cardstate *cs,
                 cs->at_state.pending_commands &= ~PC_INIT;
                 cs->cur_at_seq = SEQ_NONE;
                 atomic_set(&cs->mode, M_UNIMODEM);
-                if (!atomic_read(&cs->cidmode)) {
+                spin_lock_irqsave(&cs->lock, flags);
+                if (!cs->cidmode) {
+                        spin_unlock_irqrestore(&cs->lock, flags);
                         gigaset_free_channels(cs);
                         atomic_set(&cs->mstate, MS_READY);
                         break;
                 }
+                spin_unlock_irqrestore(&cs->lock, flags);
                 cs->at_state.pending_commands |= PC_CIDMODE;
                 atomic_set(&cs->commands_pending, 1);
                 gig_dbg(DEBUG_CMD, "Scheduling PC_CIDMODE");
@@ -1536,8 +1550,9 @@ static void do_action(int action, struct cardstate *cs,
 
         /* events from the proc file system */ // FIXME without ACT_xxxx?
         case ACT_PROC_CIDMODE:
-                if (ev->parameter != atomic_read(&cs->cidmode)) {
-                        atomic_set(&cs->cidmode, ev->parameter);
+                spin_lock_irqsave(&cs->lock, flags);
+                if (ev->parameter != cs->cidmode) {
+                        cs->cidmode = ev->parameter;
                         if (ev->parameter) {
                                 cs->at_state.pending_commands |= PC_CIDMODE;
                                 gig_dbg(DEBUG_CMD, "Scheduling PC_CIDMODE");
@@ -1547,6 +1562,7 @@ static void do_action(int action, struct cardstate *cs,
                         }
                         atomic_set(&cs->commands_pending, 1);
                 }
+                spin_unlock_irqrestore(&cs->lock, flags);
                 cs->waiting = 0;
                 wake_up(&cs->waitqueue);
                 break;
@@ -1615,8 +1631,9 @@ static void process_event(struct cardstate *cs, struct event_t *ev)
         /* Setting the pointer to the dial array */
         rep = at_state->replystruct;
 
+        spin_lock_irqsave(&cs->lock, flags);
         if (ev->type == EV_TIMEOUT) {
-                if (ev->parameter != atomic_read(&at_state->timer_index)
+                if (ev->parameter != at_state->timer_index
                     || !at_state->timer_active) {
                         ev->type = RSP_NONE; /* old timeout */
                         gig_dbg(DEBUG_ANY, "old timeout");
@@ -1625,6 +1642,7 @@ static void process_event(struct cardstate *cs, struct event_t *ev)
                 else
                         gig_dbg(DEBUG_ANY, "stopped waiting");
         }
+        spin_unlock_irqrestore(&cs->lock, flags);
 
         /* if the response belongs to a variable in at_state->int_var[VAR_XXXX]
            or at_state->str_var[STR_XXXX], set it */
@@ -1686,7 +1704,7 @@ static void process_event(struct cardstate *cs, struct event_t *ev)
                 } else {
                         /* Send command to modem if not NULL... */
                         if (p_command/*rep->command*/) {
-                                if (atomic_read(&cs->connected))
+                                if (cs->connected)
                                         send_command(cs, p_command,
                                                      sendcid, cs->dle,
                                                      GFP_ATOMIC);
@@ -1703,8 +1721,7 @@ static void process_event(struct cardstate *cs, struct event_t *ev)
                         } else if (rep->timeout > 0) { /* new timeout */
                                 at_state->timer_expires = rep->timeout * 10;
                                 at_state->timer_active = 1;
-                                new_index(&at_state->timer_index,
-                                          MAX_TIMER_INDEX);
+                                ++at_state->timer_index;
                         }
                         spin_unlock_irqrestore(&cs->lock, flags);
                 }
@@ -1724,6 +1741,7 @@ static void process_command_flags(struct cardstate *cs)
         struct bc_state *bcs;
         int i;
         int sequence;
+        unsigned long flags;
 
         atomic_set(&cs->commands_pending, 0);
 
@@ -1773,8 +1791,9 @@ static void process_command_flags(struct cardstate *cs)
         }
 
         /* only switch back to unimodem mode, if no commands are pending and no channels are up */
+        spin_lock_irqsave(&cs->lock, flags);
         if (cs->at_state.pending_commands == PC_UMMODE
-            && !atomic_read(&cs->cidmode)
+            && !cs->cidmode
             && list_empty(&cs->temp_at_states)
             && atomic_read(&cs->mode) == M_CID) {
                 sequence = SEQ_UMMODE;
@@ -1788,6 +1807,7 @@ static void process_command_flags(struct cardstate *cs)
                         }
                 }
         }
+        spin_unlock_irqrestore(&cs->lock, flags);
         cs->at_state.pending_commands &= ~PC_UMMODE;
         if (sequence != SEQ_NONE) {
                 schedule_sequence(cs, at_state, sequence);
@@ -1900,18 +1920,21 @@ static void process_events(struct cardstate *cs)
         int i;
         int check_flags = 0;
         int was_busy;
+        unsigned long flags;
 
-        /* no locking needed (only one reader) */
-        head = atomic_read(&cs->ev_head);
+        spin_lock_irqsave(&cs->ev_lock, flags);
+        head = cs->ev_head;
 
         for (i = 0; i < 2 * MAX_EVENTS; ++i) {
-                tail = atomic_read(&cs->ev_tail);
+                tail = cs->ev_tail;
                 if (tail == head) {
                         if (!check_flags && !atomic_read(&cs->commands_pending))
                                 break;
                         check_flags = 0;
+                        spin_unlock_irqrestore(&cs->ev_lock, flags);
                         process_command_flags(cs);
-                        tail = atomic_read(&cs->ev_tail);
+                        spin_lock_irqsave(&cs->ev_lock, flags);
+                        tail = cs->ev_tail;
                         if (tail == head) {
                                 if (!atomic_read(&cs->commands_pending))
                                         break;
@@ -1921,16 +1944,20 @@ static void process_events(struct cardstate *cs)
 
                 ev = cs->events + head;
                 was_busy = cs->cur_at_seq != SEQ_NONE;
+                spin_unlock_irqrestore(&cs->ev_lock, flags);
                 process_event(cs, ev);
+                spin_lock_irqsave(&cs->ev_lock, flags);
                 kfree(ev->ptr);
                 ev->ptr = NULL;
                 if (was_busy && cs->cur_at_seq == SEQ_NONE)
                         check_flags = 1;
 
                 head = (head + 1) % MAX_EVENTS;
-                atomic_set(&cs->ev_head, head);
+                cs->ev_head = head;
         }
 
+        spin_unlock_irqrestore(&cs->ev_lock, flags);
+
         if (i == 2 * MAX_EVENTS) {
                 dev_err(cs->dev,
                         "infinite loop in process_events; aborting.\n");
diff --git a/drivers/isdn/gigaset/gigaset.h b/drivers/isdn/gigaset/gigaset.h
index 39a883ebc696..350dfcf15e6c 100644
--- a/drivers/isdn/gigaset/gigaset.h
+++ b/drivers/isdn/gigaset/gigaset.h
@@ -55,9 +55,6 @@
 #define GIG_RETRYCID
 #define GIG_X75
 
-#define MAX_TIMER_INDEX 1000
-#define MAX_SEQ_INDEX   1000
-
 #define GIG_TICK 100            /* in milliseconds */
 
 /* timeout values (unit: 1 sec) */
@@ -375,7 +372,7 @@ struct at_state_t {
         struct list_head        list;
         int                     waiting;
         int                     getstring;
-        atomic_t                timer_index;
+        unsigned                timer_index;
         unsigned long           timer_expires;
         int                     timer_active;
         unsigned int            ConState;       /* State of connection */
@@ -384,7 +381,7 @@ struct at_state_t {
         int                     int_var[VAR_NUM];       /* see VAR_XXXX */
         char                    *str_var[STR_NUM];      /* see STR_XXXX */
         unsigned                pending_commands;       /* see PC_XXXX */
-        atomic_t                seq_index;
+        unsigned                seq_index;
 
         struct cardstate        *cs;
         struct bc_state         *bcs;
@@ -484,10 +481,11 @@ struct cardstate {
         unsigned fwver[4];
         int gotfwver;
 
-        atomic_t running;               /* !=0 if events are handled */
-        atomic_t connected;             /* !=0 if hardware is connected */
+        unsigned running;               /* !=0 if events are handled */
+        unsigned connected;             /* !=0 if hardware is connected */
+        unsigned isdn_up;               /* !=0 after ISDN_STAT_RUN */
 
-        atomic_t cidmode;
+        unsigned cidmode;
 
         int myid;                       /* id for communication with LL */
         isdn_if iif;
@@ -528,7 +526,7 @@ struct cardstate {
 
         /* event queue */
         struct event_t events[MAX_EVENTS];
-        atomic_t ev_tail, ev_head;
+        unsigned ev_tail, ev_head;
         spinlock_t ev_lock;
 
         /* current modem response */
@@ -824,7 +822,7 @@ static inline void gigaset_schedule_event(struct cardstate *cs)
 {
         unsigned long flags;
         spin_lock_irqsave(&cs->lock, flags);
-        if (atomic_read(&cs->running))
+        if (cs->running)
                 tasklet_schedule(&cs->event_tasklet);
         spin_unlock_irqrestore(&cs->lock, flags);
 }
diff --git a/drivers/isdn/gigaset/i4l.c b/drivers/isdn/gigaset/i4l.c
index 7059b84b96a7..0815dbfb8291 100644
--- a/drivers/isdn/gigaset/i4l.c
+++ b/drivers/isdn/gigaset/i4l.c
@@ -56,11 +56,6 @@ static int writebuf_from_LL(int driverID, int channel, int ack,
                 "Receiving data from LL (id: %d, ch: %d, ack: %d, sz: %d)",
                 driverID, channel, ack, len);
 
-        if (!atomic_read(&cs->connected)) {
-                err("%s: disconnected", __func__);
-                return -ENODEV;
-        }
-
         if (!len) {
                 if (ack)
                         notice("%s: not ACKing empty packet", __func__);
@@ -78,7 +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);
+        return cs->ops->send_skb(bcs, skb); //FIXME cs->ops->send_skb() must handle !cs->connected correctly
 }
 
 void gigaset_skb_sent(struct bc_state *bcs, struct sk_buff *skb)
@@ -119,11 +114,12 @@ static int command_from_LL(isdn_ctrl *cntrl)
         struct bc_state *bcs;
         int retval = 0;
         struct setup_parm *sp;
+        unsigned param;
+        unsigned long flags;
 
         gigaset_debugdrivers();
 
-        //FIXME "remove test for &connected"
-        if ((!cs || !atomic_read(&cs->connected))) {
+        if (!cs) {
                 warn("LL tried to access unknown device with nr. %d",
                      cntrl->driver);
                 return -ENODEV;
@@ -166,8 +162,11 @@ static int command_from_LL(isdn_ctrl *cntrl)
                 }
                 *sp = cntrl->parm.setup;
 
-                if (!gigaset_add_event(cs, &bcs->at_state, EV_DIAL, sp,
-                                       atomic_read(&bcs->at_state.seq_index),
+                spin_lock_irqsave(&cs->lock, flags);
+                param = bcs->at_state.seq_index;
+                spin_unlock_irqrestore(&cs->lock, flags);
+
+                if (!gigaset_add_event(cs, &bcs->at_state, EV_DIAL, sp, param,
                                        NULL)) {
                         //FIXME what should we do?
                         kfree(sp);
diff --git a/drivers/isdn/gigaset/interface.c b/drivers/isdn/gigaset/interface.c
index ac408acaaf17..08e4c4eea14d 100644
--- a/drivers/isdn/gigaset/interface.c
+++ b/drivers/isdn/gigaset/interface.c
@@ -33,7 +33,7 @@ static int if_lock(struct cardstate *cs, int *arg)
         }
 
         if (!cmd && atomic_read(&cs->mstate) == MS_LOCKED
-            && atomic_read(&cs->connected)) {
+            && cs->connected) {
                 cs->ops->set_modem_ctrl(cs, 0, TIOCM_DTR|TIOCM_RTS);
                 cs->ops->baud_rate(cs, B115200);
                 cs->ops->set_line_ctrl(cs, CS8);
@@ -107,6 +107,11 @@ static int if_config(struct cardstate *cs, int *arg)
         if (atomic_read(&cs->mstate) != MS_LOCKED)
                 return -EBUSY;
 
+        if (!cs->connected) {
+                err("not connected!");
+                return -ENODEV;
+        }
+
         *arg = 0;
         return gigaset_enterconfigmode(cs);
 }
@@ -246,7 +251,7 @@ static int if_ioctl(struct tty_struct *tty, struct file *file,
                         break;
                 case GIGASET_BRKCHARS:
                         //FIXME test if MS_LOCKED
-                        if (!atomic_read(&cs->connected)) {
+                        if (!cs->connected) {
                                 gig_dbg(DEBUG_ANY,
                                     "can't communicate with unplugged device");
                                 retval = -ENODEV;
@@ -327,7 +332,7 @@ static int if_tiocmset(struct tty_struct *tty, struct file *file,
         if (mutex_lock_interruptible(&cs->mutex))
                 return -ERESTARTSYS; // FIXME -EINTR?
 
-        if (!atomic_read(&cs->connected)) {
+        if (!cs->connected) {
                 gig_dbg(DEBUG_ANY, "can't communicate with unplugged device");
                 retval = -ENODEV;
         } else {
@@ -362,7 +367,7 @@ static int if_write(struct tty_struct *tty, const unsigned char *buf, int count)
         else if (atomic_read(&cs->mstate) != MS_LOCKED) {
                 warn("can't write to unlocked device");
                 retval = -EBUSY;
-        } else if (!atomic_read(&cs->connected)) {
+        } else if (!cs->connected) {
                 gig_dbg(DEBUG_ANY, "can't write to unplugged device");
                 retval = -EBUSY; //FIXME
         } else {
@@ -396,7 +401,7 @@ static int if_write_room(struct tty_struct *tty)
         else if (atomic_read(&cs->mstate) != MS_LOCKED) {
                 warn("can't write to unlocked device");
                 retval = -EBUSY; //FIXME
-        } else if (!atomic_read(&cs->connected)) {
+        } else if (!cs->connected) {
                 gig_dbg(DEBUG_ANY, "can't write to unplugged device");
                 retval = -EBUSY; //FIXME
         } else
@@ -428,7 +433,7 @@ static int if_chars_in_buffer(struct tty_struct *tty)
         else if (atomic_read(&cs->mstate) != MS_LOCKED) {
                 warn("can't write to unlocked device");
                 retval = -EBUSY;
-        } else if (!atomic_read(&cs->connected)) {
+        } else if (!cs->connected) {
                 gig_dbg(DEBUG_ANY, "can't write to unplugged device");
                 retval = -EBUSY; //FIXME
         } else
@@ -508,7 +513,7 @@ static void if_set_termios(struct tty_struct *tty, struct termios *old)
                 goto out;
         }
 
-        if (!atomic_read(&cs->connected)) {
+        if (!cs->connected) {
                 gig_dbg(DEBUG_ANY, "can't communicate with unplugged device");
                 goto out;
         }
diff --git a/drivers/isdn/gigaset/isocdata.c b/drivers/isdn/gigaset/isocdata.c
index 2f1628734a38..45f017ed6e8c 100644
--- a/drivers/isdn/gigaset/isocdata.c
+++ b/drivers/isdn/gigaset/isocdata.c
@@ -990,13 +990,17 @@ void gigaset_isoc_input(struct inbuf_t *inbuf)
 int gigaset_isoc_send_skb(struct bc_state *bcs, struct sk_buff *skb)
 {
         int len = skb->len;
+        unsigned long flags;
 
         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 */
-        tasklet_schedule(&bcs->hw.bas->sent_tasklet);
+        spin_lock_irqsave(&bcs->cs->lock, flags);
+        if (bcs->cs->connected)
+                tasklet_schedule(&bcs->hw.bas->sent_tasklet);
+        spin_unlock_irqrestore(&bcs->cs->lock, flags);
 
         return len;     /* ok so far */
 }
diff --git a/drivers/isdn/gigaset/proc.c b/drivers/isdn/gigaset/proc.c
index 80d8ef1874f3..d267a636b53c 100644
--- a/drivers/isdn/gigaset/proc.c
+++ b/drivers/isdn/gigaset/proc.c
@@ -19,8 +19,15 @@
 static ssize_t show_cidmode(struct device *dev, struct device_attribute *attr,
                             char *buf)
 {
+        int ret;
+        unsigned long flags;
         struct cardstate *cs = dev_get_drvdata(dev);
-        return sprintf(buf, "%d\n", atomic_read(&cs->cidmode));
+
+        spin_lock_irqsave(&cs->lock, flags);
+        ret = sprintf(buf, "%u\n", cs->cidmode);
+        spin_unlock_irqrestore(&cs->lock, flags);
+
+        return ret;
 }
 
 static ssize_t set_cidmode(struct device *dev, struct device_attribute *attr,
diff --git a/drivers/isdn/gigaset/usb-gigaset.c b/drivers/isdn/gigaset/usb-gigaset.c
index fe8435b8fa97..bfb73fd5077e 100644
--- a/drivers/isdn/gigaset/usb-gigaset.c
+++ b/drivers/isdn/gigaset/usb-gigaset.c
@@ -371,13 +371,14 @@ static void gigaset_read_int_callback(struct urb *urb, struct pt_regs *regs)
         int r;
         unsigned numbytes;
         unsigned char *src;
-
-        if (!atomic_read(&cs->connected)) {
-                err("%s: disconnected", __func__);
-                return;
-        }
+        unsigned long flags;
 
         if (!urb->status) {
+                if (!cs->connected) {
+                        err("%s: disconnected", __func__); /* should never happen */
+                        return;
+                }
+
                 numbytes = urb->actual_length;
 
                 if (numbytes) {
@@ -399,12 +400,19 @@ static void gigaset_read_int_callback(struct urb *urb, struct pt_regs *regs)
                 /* The urb might have been killed. */
                 gig_dbg(DEBUG_ANY, "%s - nonzero read bulk status received: %d",
                         __func__, urb->status);
-                if (urb->status != -ENOENT) /* not killed */
+                if (urb->status != -ENOENT) { /* not killed */
+                        if (!cs->connected) {
+                                err("%s: disconnected", __func__); /* should never happen */
+                                return;
+                        }
                         resubmit = 1;
+                }
         }
 
         if (resubmit) {
-                r = usb_submit_urb(urb, SLAB_ATOMIC);
+                spin_lock_irqsave(&cs->lock, flags);
+                r = cs->connected ? usb_submit_urb(urb, SLAB_ATOMIC) : -ENODEV;
+                spin_unlock_irqrestore(&cs->lock, flags);
                 if (r)
                         dev_err(cs->dev, "error %d when resubmitting urb.\n",
                                 -r);
@@ -416,21 +424,22 @@ static void gigaset_read_int_callback(struct urb *urb, struct pt_regs *regs)
 static void gigaset_write_bulk_callback(struct urb *urb, struct pt_regs *regs)
 {
         struct cardstate *cs = urb->context;
+        unsigned long flags;
 
-#ifdef CONFIG_GIGASET_DEBUG
-        if (!atomic_read(&cs->connected)) {
-                err("%s: not connected", __func__);
-                return;
-        }
-#endif
         if (urb->status)
                 dev_err(cs->dev, "bulk transfer failed (status %d)\n",
                         -urb->status);
                 /* That's all we can do. Communication problems
                    are handled by timeouts or network protocols. */
 
-        atomic_set(&cs->hw.usb->busy, 0);
-        tasklet_schedule(&cs->write_tasklet);
+        spin_lock_irqsave(&cs->lock, flags);
+        if (!cs->connected) {
+                err("%s: not connected", __func__);
+        } else {
+                atomic_set(&cs->hw.usb->busy, 0);
+                tasklet_schedule(&cs->write_tasklet);
+        }
+        spin_unlock_irqrestore(&cs->lock, flags);
 }
 
 static int send_cb(struct cardstate *cs, struct cmdbuf_t *cb)
@@ -465,6 +474,8 @@ static int send_cb(struct cardstate *cs, struct cmdbuf_t *cb)
                 }
                 if (cb) {
                         count = min(cb->len, ucs->bulk_out_size);
+                        gig_dbg(DEBUG_OUTPUT, "send_cb: send %d bytes", count);
+
                         usb_fill_bulk_urb(ucs->bulk_out_urb, ucs->udev,
                                           usb_sndbulkpipe(ucs->udev,
                                              ucs->bulk_out_endpointAddr & 0x0f),
@@ -474,14 +485,15 @@ static int send_cb(struct cardstate *cs, struct cmdbuf_t *cb)
                         cb->offset += count;
                         cb->len -= count;
                         atomic_set(&ucs->busy, 1);
-                        gig_dbg(DEBUG_OUTPUT, "send_cb: send %d bytes", count);
 
-                        status = usb_submit_urb(ucs->bulk_out_urb, SLAB_ATOMIC);
+                        spin_lock_irqsave(&cs->lock, flags);
+                        status = cs->connected ? usb_submit_urb(ucs->bulk_out_urb, SLAB_ATOMIC) : -ENODEV;
+                        spin_unlock_irqrestore(&cs->lock, flags);
+
                         if (status) {
                                 atomic_set(&ucs->busy, 0);
-                                dev_err(cs->dev,
-                                        "could not submit urb (error %d)\n",
-                                        -status);
+                                err("could not submit urb (error %d)\n",
+                                    -status);
                                 cb->len = 0; /* skip urb => remove cb+wakeup
                                                 in next loop cycle */
                         }
@@ -502,11 +514,6 @@ static int gigaset_write_cmd(struct cardstate *cs, const unsigned char *buf,
                              DEBUG_TRANSCMD : DEBUG_LOCKCMD,
                            "CMD Transmit", len, buf);
 
-        if (!atomic_read(&cs->connected)) {
-                err("%s: not connected", __func__);
-                return -ENODEV;
-        }
-
         if (len <= 0)
                 return 0;
 
@@ -533,7 +540,10 @@ static int gigaset_write_cmd(struct cardstate *cs, const unsigned char *buf,
         cs->lastcmdbuf = cb;
         spin_unlock_irqrestore(&cs->cmdlock, flags);
 
-        tasklet_schedule(&cs->write_tasklet);
+        spin_lock_irqsave(&cs->lock, flags);
+        if (cs->connected)
+                tasklet_schedule(&cs->write_tasklet);
+        spin_unlock_irqrestore(&cs->lock, flags);
         return len;
 }
 
@@ -629,6 +639,7 @@ static int write_modem(struct cardstate *cs)
         int count;
         struct bc_state *bcs = &cs->bcs[0]; /* only one channel */
         struct usb_cardstate *ucs = cs->hw.usb;
+        unsigned long flags;
 
         gig_dbg(DEBUG_WRITE, "len: %d...", bcs->tx_skb->len);
 
@@ -644,20 +655,27 @@ static int write_modem(struct cardstate *cs)
         count = min(bcs->tx_skb->len, (unsigned) ucs->bulk_out_size);
         memcpy(ucs->bulk_out_buffer, bcs->tx_skb->data, count);
         skb_pull(bcs->tx_skb, count);
-
-        usb_fill_bulk_urb(ucs->bulk_out_urb, ucs->udev,
-                          usb_sndbulkpipe(ucs->udev,
-                                          ucs->bulk_out_endpointAddr & 0x0f),
-                          ucs->bulk_out_buffer, count,
-                          gigaset_write_bulk_callback, cs);
         atomic_set(&ucs->busy, 1);
         gig_dbg(DEBUG_OUTPUT, "write_modem: send %d bytes", count);
 
-        ret = usb_submit_urb(ucs->bulk_out_urb, SLAB_ATOMIC);
+        spin_lock_irqsave(&cs->lock, flags);
+        if (cs->connected) {
+                usb_fill_bulk_urb(ucs->bulk_out_urb, ucs->udev,
+                                  usb_sndbulkpipe(ucs->udev,
+                                                  ucs->bulk_out_endpointAddr & 0x0f),
+                                  ucs->bulk_out_buffer, count,
+                                  gigaset_write_bulk_callback, cs);
+                ret = usb_submit_urb(ucs->bulk_out_urb, SLAB_ATOMIC);
+        } else {
+                ret = -ENODEV;
+        }
+        spin_unlock_irqrestore(&cs->lock, flags);
+
         if (ret) {
-                dev_err(cs->dev, "could not submit urb (error %d)\n", -ret);
+                err("could not submit urb (error %d)\n", -ret);
                 atomic_set(&ucs->busy, 0);
         }
+
         if (!bcs->tx_skb->len) {
                 /* skb sent completely */
                 gigaset_skb_sent(bcs, bcs->tx_skb); //FIXME also, when ret<0?