This is a note to let you know that I've just added the patch titled usb: dwc3: gadget: fix for short pkts during chained xfers to the 4.7-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-for-short-pkts-during-chained-xfers.patch and it can be found in the queue-4.7 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From e5b36ae2f851024d43c76e51f395d32ce8d769ce Mon Sep 17 00:00:00 2001 From: Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx> Date: Wed, 10 Aug 2016 11:13:26 +0300 Subject: usb: dwc3: gadget: fix for short pkts during chained xfers From: Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx> commit e5b36ae2f851024d43c76e51f395d32ce8d769ce upstream. DWC3 has one interesting peculiarity with chained transfers. If we setup N chained transfers and we get a short packet before processing all N TRBs, DWC3 will (conditionally) issue a XferComplete or XferInProgress event and retire all TRBs from the one which got a short packet to the last without clearing their HWO bits. This means SW must clear HWO bit manually, which this patch is doing. Cc: Brian E Rogers <brian.e.rogers@xxxxxxxxx> Signed-off-by: Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/usb/dwc3/gadget.c | 23 ++++++++++++++++++++--- 1 file changed, 20 insertions(+), 3 deletions(-) --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -1897,7 +1897,8 @@ static void dwc3_gadget_free_endpoints(s static int __dwc3_cleanup_done_trbs(struct dwc3 *dwc, struct dwc3_ep *dep, struct dwc3_request *req, struct dwc3_trb *trb, - const struct dwc3_event_depevt *event, int status) + const struct dwc3_event_depevt *event, int status, + int chain) { unsigned int count; unsigned int s_pkt = 0; @@ -1905,6 +1906,19 @@ static int __dwc3_cleanup_done_trbs(stru trace_dwc3_complete_trb(dep, trb); + /* + * If we're in the middle of series of chained TRBs and we + * receive a short transfer along the way, DWC3 will skip + * through all TRBs including the last TRB in the chain (the + * where CHN bit is zero. DWC3 will also avoid clearing HWO + * bit and SW has to do it manually. + * + * We're going to do that here to avoid problems of HW trying + * to use bogus TRBs for transfers. + */ + if (chain && (trb->ctrl & DWC3_TRB_CTRL_HWO)) + trb->ctrl &= ~DWC3_TRB_CTRL_HWO; + if ((trb->ctrl & DWC3_TRB_CTRL_HWO) && status != -ESHUTDOWN) /* * We continue despite the error. There is not much we @@ -1916,6 +1930,7 @@ static int __dwc3_cleanup_done_trbs(stru */ dev_err(dwc->dev, "%s's TRB (%p) still owned by HW\n", dep->name, trb); + count = trb->size & DWC3_TRB_SIZE_MASK; if (dep->direction) { @@ -1977,10 +1992,13 @@ static int dwc3_cleanup_done_reqs(struct int ret; do { + int chain; + req = next_request(&dep->started_list); if (WARN_ON_ONCE(!req)) return 1; + chain = req->request.num_mapped_sgs > 0; i = 0; do { slot = req->first_trb_index + i; @@ -1990,9 +2008,8 @@ static int dwc3_cleanup_done_reqs(struct trb = &dep->trb_pool[slot]; count += trb->size & DWC3_TRB_SIZE_MASK; - ret = __dwc3_cleanup_done_trbs(dwc, dep, req, trb, - event, status); + event, status, chain); if (ret) break; } while (++i < req->request.num_mapped_sgs); Patches currently in stable-queue which might be from felipe.balbi@xxxxxxxxxxxxxxx are queue-4.7/usb-dwc3-pci-add-intel-kabylake-pci-id.patch queue-4.7/usb-misc-usbtest-usbtest_do_ioctl-may-return-positive-integer.patch queue-4.7/usb-renesas_usbhs-fix-receiving-data-corrupt-on-r-car-gen3-with-dmac.patch queue-4.7/usb-renesas_usbhs-clear-the-brdysts-in-usbhsg_ep_enable.patch queue-4.7/usb-gadget-fix-gadgetfs-aio-support.patch queue-4.7/usb-dwc3-gadget-always-cleanup-all-trbs.patch queue-4.7/usb-renesas_usbhs-use-dmac-only-if-the-pipe-type-is-bulk.patch queue-4.7/usb-gadget-fsl_qe_udc-off-by-one-in-setup_received_handle.patch queue-4.7/usb-dwc3-gadget-fix-for-short-pkts-during-chained-xfers.patch queue-4.7/usb-dwc3-gadget-increment-request-actual-once.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