[PATCH 4.19 005/101] usb: dwc3: gadget: Reclaim extra TRBs after request completion

From: Greg Kroah-Hartman
Date: Tue Nov 17 2020 - 09:00:26 EST


From: Thinh Nguyen <Thinh.Nguyen@xxxxxxxxxxxx>

[ Upstream commit 690e5c2dc29f8891fcfd30da67e0d5837c2c9df5 ]

An SG request may be partially completed (due to no available TRBs).
Don't reclaim extra TRBs and clear the needs_extra_trb flag until the
request is fully completed. Otherwise, the driver will reclaim the wrong
TRB.

Cc: stable@xxxxxxxxxxxxxxx
Fixes: 1f512119a08c ("usb: dwc3: gadget: add remaining sg entries to ring")
Signed-off-by: Thinh Nguyen <Thinh.Nguyen@xxxxxxxxxxxx>
Signed-off-by: Felipe Balbi <balbi@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/usb/dwc3/gadget.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index f24cfb3a6907b..6ab5c48f5d873 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -2386,6 +2386,11 @@ static int dwc3_gadget_ep_cleanup_completed_request(struct dwc3_ep *dep,
ret = dwc3_gadget_ep_reclaim_trb_linear(dep, req, event,
status);

+ req->request.actual = req->request.length - req->remaining;
+
+ if (!dwc3_gadget_ep_request_completed(req))
+ goto out;
+
if (req->needs_extra_trb) {
unsigned int maxp = usb_endpoint_maxp(dep->endpoint.desc);

@@ -2401,11 +2406,6 @@ static int dwc3_gadget_ep_cleanup_completed_request(struct dwc3_ep *dep,
req->needs_extra_trb = false;
}

- req->request.actual = req->request.length - req->remaining;
-
- if (!dwc3_gadget_ep_request_completed(req))
- goto out;
-
dwc3_gadget_giveback(dep, req, status);

out:
--
2.27.0