Patch "usb: dwc3: ep0: fix DMA starvation by assigning req->trb on ep0" has been added to the 4.13-stable tree

[<gregkh@linuxfoundation.org>]

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

    usb: dwc3: ep0: fix DMA starvation by assigning req->trb on ep0

to the 4.13-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-ep0-fix-dma-starvation-by-assigning-req-trb-on-ep0.patch
and it can be found in the queue-4.13 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 55168470835688e5da5828cdcf1b1498d7baadb1 Mon Sep 17 00:00:00 2001
From: Felipe Balbi <felipe.balbi@linux.intel.com>
Date: Mon, 11 Sep 2017 10:45:12 +0300
Subject: usb: dwc3: ep0: fix DMA starvation by assigning req->trb on ep0

From: Felipe Balbi <felipe.balbi@linux.intel.com>

commit 55168470835688e5da5828cdcf1b1498d7baadb1 upstream.

If we don't assign a TRB to ep0 requests, we won't be able to unmap
the request later on resulting in starvation of DMA resources.

Fixes: 4a71fcb8ac5f ("usb: dwc3: gadget: only unmap requests from DMA if mapped")
Reported-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Tested-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/usb/dwc3/ep0.c |    7 +++++++
 1 file changed, 7 insertions(+)

--- a/drivers/usb/dwc3/ep0.c
+++ b/drivers/usb/dwc3/ep0.c
@@ -990,6 +990,8 @@ static void __dwc3_ep0_do_control_data(s
 					 DWC3_TRBCTL_CONTROL_DATA,
 					 true);
 
+		req->trb = &dwc->ep0_trb[dep->trb_enqueue - 1];
+
 		/* Now prepare one extra TRB to align transfer size */
 		dwc3_ep0_prepare_one_trb(dep, dwc->bounce_addr,
 					 maxpacket - rem,
@@ -1015,6 +1017,8 @@ static void __dwc3_ep0_do_control_data(s
 					 DWC3_TRBCTL_CONTROL_DATA,
 					 true);
 
+		req->trb = &dwc->ep0_trb[dep->trb_enqueue - 1];
+
 		/* Now prepare one extra TRB to align transfer size */
 		dwc3_ep0_prepare_one_trb(dep, dwc->bounce_addr,
 					 0, DWC3_TRBCTL_CONTROL_DATA,
@@ -1029,6 +1033,9 @@ static void __dwc3_ep0_do_control_data(s
 		dwc3_ep0_prepare_one_trb(dep, req->request.dma,
 				req->request.length, DWC3_TRBCTL_CONTROL_DATA,
 				false);
+
+		req->trb = &dwc->ep0_trb[dep->trb_enqueue];
+
 		ret = dwc3_ep0_start_trans(dep);
 	}
 


Patches currently in stable-queue which might be from felipe.balbi@linux.intel.com are

queue-4.13/usb-dwc3-ep0-fix-dma-starvation-by-assigning-req-trb-on-ep0.patch