This is a note to let you know that I've just added the patch titled
usb: dwc3: gadget: Reset num TRBs before giving back the request
to the 5.4-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-reset-num-trbs-before-giving-back-the-request.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 00f8205ffcf112dcef14f8151d78075d38d22c08 Mon Sep 17 00:00:00 2001
From: Elson Roy Serrao <quic_eserrao@xxxxxxxxxxx>
Date: Thu, 1 Jun 2023 14:27:30 -0700
Subject: usb: dwc3: gadget: Reset num TRBs before giving back the request
From: Elson Roy Serrao <quic_eserrao@xxxxxxxxxxx>
commit 00f8205ffcf112dcef14f8151d78075d38d22c08 upstream.
Consider a scenario where cable disconnect happens when there is an active
usb reqest queued to the UDC. As part of the disconnect we would issue an
end transfer with no interrupt-on-completion before giving back this
request. Since we are giving back the request without skipping TRBs the
num_trbs field of dwc3_request still holds the stale value previously used.
Function drivers re-use same request for a given bind-unbind session and
hence their dwc3_request context gets preserved across cable
disconnect/connect. When such a request gets re-queued after cable connect,
we would increase the num_trbs field on top of the previous stale value
thus incorrectly representing the number of TRBs used. Fix this by
resetting num_trbs field before giving back the request.
Fixes: 09fe1f8d7e2f ("usb: dwc3: gadget: track number of TRBs per request")
Cc: stable <stable@xxxxxxxxxx>
Signed-off-by: Elson Roy Serrao <quic_eserrao@xxxxxxxxxxx>
Acked-by: Thinh Nguyen <Thinh.Nguyen@xxxxxxxxxxxx>
Message-ID: <1685654850-8468-1-git-send-email-quic_eserrao@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/usb/dwc3/gadget.c | 1 +
1 file changed, 1 insertion(+)
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -177,6 +177,7 @@ static void dwc3_gadget_del_and_unmap_re
list_del(&req->list);
req->remaining = 0;
req->needs_extra_trb = false;
+ req->num_trbs = 0;
if (req->request.status == -EINPROGRESS)
req->request.status = status;
Patches currently in stable-queue which might be from quic_eserrao@xxxxxxxxxxx are
queue-5.4/usb-dwc3-gadget-reset-num-trbs-before-giving-back-the-request.patch
