[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>
diff --git a/drivers/isdn/gigaset/usb-gigaset.c b/drivers/isdn/gigaset/usb-gigaset.c
index fe8435b..bfb73fd 100644
--- a/drivers/isdn/gigaset/usb-gigaset.c
+++ b/drivers/isdn/gigaset/usb-gigaset.c
@@ -371,13 +371,14 @@
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 @@
/* 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_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 @@
}
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 @@
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 @@
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 @@
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 @@
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 @@
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?