[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>

1 files changed, 22 insertions, 26 deletions

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;
 }