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| author | Eugeny S. Mints <emints@ru.mvista.com> | 2006-09-02 12:59:19 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2006-09-27 20:58:56 +0200 |
| commit | 80f8af0c59385b41564a3ae670f94a1b4caa43b2 (patch) | |
| tree | c2721898c3db66f743639a8446d72c48ebd11950 /drivers/usb/gadget | |
| parent | USB: replace kernel_thread() with kthread_run() in libusual.c (diff) | |
| download | linux-80f8af0c59385b41564a3ae670f94a1b4caa43b2.tar.xz linux-80f8af0c59385b41564a3ae670f94a1b4caa43b2.zip | |
USB: usb serial gadget smp related bug
Adjust dev->dev_lock spinlock lock/unlock calls to be safe for SMP case.
Otherwise the following sequence may lead to a deadlock in SMP case:
gs_send()->usb_ep_queue()
->(in case a request is satisfied immediatly) gs_write_complete()
for ex for pxa2xx_udc.c:
usb_ep_queue()->pxa2xx_ep_queue()->write_fifo()->done()->gs_write_complete()
(through req.complete pointer)
Signed-off-by: Eugeny S. Mints <emints@ru.mvista.com>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/usb/gadget')
| -rw-r--r-- | drivers/usb/gadget/serial.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/usb/gadget/serial.c b/drivers/usb/gadget/serial.c index e762aa19ab0a..b893e3118e1b 100644 --- a/drivers/usb/gadget/serial.c +++ b/drivers/usb/gadget/serial.c @@ -1120,12 +1120,15 @@ static int gs_send(struct gs_dev *dev) gs_debug_level(3, "gs_send: len=%d, 0x%2.2x 0x%2.2x 0x%2.2x ...\n", len, *((unsigned char *)req->buf), *((unsigned char *)req->buf+1), *((unsigned char *)req->buf+2)); list_del(&req_entry->re_entry); req->length = len; + spin_unlock_irqrestore(&dev->dev_lock, flags); if ((ret=usb_ep_queue(ep, req, GFP_ATOMIC))) { printk(KERN_ERR "gs_send: cannot queue read request, ret=%d\n", ret); + spin_lock_irqsave(&dev->dev_lock, flags); break; } + spin_lock_irqsave(&dev->dev_lock, flags); } else { break; } |