patch "usb: dwc3: gadget: Properly check last unaligned/zero chain TRB" added to usb-linus

This is a note to let you know that I've just added the patch titled

usb: dwc3: gadget: Properly check last unaligned/zero chain TRB

to my usb git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-linus branch.

The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)

The patch will hopefully also be merged in Linus's tree for the next -rc kernel release.

If you have any questions about this process, please let me know.

From: Thinh Nguyen <[email protected]>
Date: Thu, 2 Aug 2018 20:17:16 -0700
Subject: usb: dwc3: gadget: Properly check last unaligned/zero chain TRB

Current check for the last extra TRB for zero and unaligned transfers does not account for isoc OUT. The last TRB of the Buffer Descriptor for isoc OUT transfers will be retired with HWO=0. As a result, we won't return early. The req->remaining will be updated to include the BUFSIZ count of the extra TRB, and the actual number of transferred bytes calculation will be wrong.

To fix this, check whether it's a short or zero packet and the last TRB chain bit to return early.

---
 drivers/usb/dwc3/gadget.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

index 679c12e14522..06e22afdf3d1 100644
@@ -2259,7 +2259,7 @@ static int dwc3_gadget_ep_reclaim_completed_trb(struct dwc3_ep *dep,
 	 * with one TRB pending in the ring. We need to manually clear HWO bit
 	 * from that TRB.
 	 */
-	if ((req->zero || req->unaligned) && (trb->ctrl & DWC3_TRB_CTRL_HWO)) {
+	if ((req->zero || req->unaligned) && !(trb->ctrl & DWC3_TRB_CTRL_CHN)) {
 		trb->ctrl &= ~DWC3_TRB_CTRL_HWO;
 		return 1;
 	}

2.19.1