From: Eugeny S. Mints Date: Sat, 2 Sep 2006 10:59:19 +0000 (-0700) Subject: USB: usb serial gadget smp related bug X-Git-Tag: MMI-PSA29.97-13-9~47266^2~36 X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=80f8af0c59385b41564a3ae670f94a1b4caa43b2;p=GitHub%2FMotorolaMobilityLLC%2Fkernel-slsi.git 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 Acked-by: David Brownell Signed-off-by: Greg Kroah-Hartman --- 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; }