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| author | Anton Vorontsov <avorontsov@ru.mvista.com> | 2008-12-25 17:15:05 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2009-02-09 11:19:46 -0800 |
| commit | a30551db66afa1b53a4fa7ceadddb7122bdcf491 (patch) | |
| tree | bbd4f0468a7417067bf7ebb5001368b01f8c7e90 | |
| parent | 94f341db3dd080851f918da37e84659ef760da26 (diff) | |
| download | linux-a30551db66afa1b53a4fa7ceadddb7122bdcf491.tar.gz linux-a30551db66afa1b53a4fa7ceadddb7122bdcf491.tar.bz2 linux-a30551db66afa1b53a4fa7ceadddb7122bdcf491.zip | |
USB: fsl_qe_udc: Fix recursive locking bug in ch9getstatus()
The call chain is this:
qe_udc_irq() <- grabs the udc->lock spinlock
rx_irq()
qe_ep0_rx()
ep0_setup_handle()
setup_received_handle()
ch9getstatus()
qe_ep_queue() <- tries to grab the udc->lock again
It seems unsafe to temporarily drop the lock in the ch9getstatus(),
so to fix that bug the lock-less __qe_ep_queue() function
implemented and used by the ch9getstatus().
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| -rw-r--r-- | drivers/usb/gadget/fsl_qe_udc.c | 26 |
1 files changed, 18 insertions, 8 deletions
diff --git a/drivers/usb/gadget/fsl_qe_udc.c b/drivers/usb/gadget/fsl_qe_udc.c index e8f7862acb3d..064582fb6a87 100644 --- a/drivers/usb/gadget/fsl_qe_udc.c +++ b/drivers/usb/gadget/fsl_qe_udc.c @@ -1681,14 +1681,11 @@ static void qe_free_request(struct usb_ep *_ep, struct usb_request *_req) kfree(req); } -/* queues (submits) an I/O request to an endpoint */ -static int qe_ep_queue(struct usb_ep *_ep, struct usb_request *_req, - gfp_t gfp_flags) +static int __qe_ep_queue(struct usb_ep *_ep, struct usb_request *_req) { struct qe_ep *ep = container_of(_ep, struct qe_ep, ep); struct qe_req *req = container_of(_req, struct qe_req, req); struct qe_udc *udc; - unsigned long flags; int reval; udc = ep->udc; @@ -1732,7 +1729,7 @@ static int qe_ep_queue(struct usb_ep *_ep, struct usb_request *_req, list_add_tail(&req->queue, &ep->queue); dev_vdbg(udc->dev, "gadget have request in %s! %d\n", ep->name, req->req.length); - spin_lock_irqsave(&udc->lock, flags); + /* push the request to device */ if (ep_is_in(ep)) reval = ep_req_send(ep, req); @@ -1748,11 +1745,24 @@ static int qe_ep_queue(struct usb_ep *_ep, struct usb_request *_req, if (ep->dir == USB_DIR_OUT) reval = ep_req_receive(ep, req); - spin_unlock_irqrestore(&udc->lock, flags); - return 0; } +/* queues (submits) an I/O request to an endpoint */ +static int qe_ep_queue(struct usb_ep *_ep, struct usb_request *_req, + gfp_t gfp_flags) +{ + struct qe_ep *ep = container_of(_ep, struct qe_ep, ep); + struct qe_udc *udc = ep->udc; + unsigned long flags; + int ret; + + spin_lock_irqsave(&udc->lock, flags); + ret = __qe_ep_queue(_ep, _req); + spin_unlock_irqrestore(&udc->lock, flags); + return ret; +} + /* dequeues (cancels, unlinks) an I/O request from an endpoint */ static int qe_ep_dequeue(struct usb_ep *_ep, struct usb_request *_req) { @@ -2008,7 +2018,7 @@ static void ch9getstatus(struct qe_udc *udc, u8 request_type, u16 value, udc->ep0_dir = USB_DIR_IN; /* data phase */ - status = qe_ep_queue(&ep->ep, &req->req, GFP_ATOMIC); + status = __qe_ep_queue(&ep->ep, &req->req); if (status == 0) return; |