This is a note to let you know that I've just added the patch titled usb: dwc3: gadget: Fix TRB preparation during SG to the 3.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: usb-dwc3-gadget-fix-trb-preparation-during-sg.patch and it can be found in the queue-3.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From ec512fb8e5611fed1df2895f90317ce6797d6b32 Mon Sep 17 00:00:00 2001 From: Amit Virdi <amit.virdi@xxxxxx> Date: Tue, 13 Jan 2015 14:27:20 +0530 Subject: usb: dwc3: gadget: Fix TRB preparation during SG From: Amit Virdi <amit.virdi@xxxxxx> commit ec512fb8e5611fed1df2895f90317ce6797d6b32 upstream. When scatter gather (SG) is used, multiple TRBs are prepared from one DWC3 request (dwc3_request). So while preparing TRBs, the 'last' flag should be set only when it is the last TRB being prepared from the last dwc3_request entry. The current implementation uses list_is_last to check if the dwc3_request is the last entry from the request_list. However, list_is_last returns false for the last entry too. This is because, while preparing the first TRB from a request, the function dwc3_prepare_one_trb modifies the request's next and prev pointers while moving the URB to req_queued. Hence, list_is_last always returns false no matter what. The correct way is not to access the modified pointers of dwc3_request but to use list_empty macro instead. Fixes: e5ba5ec833aa (usb: dwc3: gadget: fix scatter gather implementation) Signed-off-by: Amit Virdi <amit.virdi@xxxxxx> Signed-off-by: Felipe Balbi <balbi@xxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/usb/dwc3/gadget.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -887,8 +887,7 @@ static void dwc3_prepare_trbs(struct dwc if (i == (request->num_mapped_sgs - 1) || sg_is_last(s)) { - if (list_is_last(&req->list, - &dep->request_list)) + if (list_empty(&dep->request_list)) last_one = true; chain = false; } Patches currently in stable-queue which might be from amit.virdi@xxxxxx are queue-3.14/usb-dwc3-gadget-stop-trb-preparation-after-limit-is-reached.patch queue-3.14/usb-dwc3-gadget-fix-trb-preparation-during-sg.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html