[PATCH 4.19 16/88] usb: dwc3: gadget: Return proper request status

Greg Kroah-Hartman
2022-05-10T13:31:26Z

From: Thinh Nguyen <Thinh.Nguyen@synopsys.com>

commit c7428dbddcf4ea1919e1c8e15f715b94ca359268 upstream.

If the user sets the usb_request's no_interrupt, then there will be no
completion event for the request. Currently the driver incorrectly uses
the event status of a different request to report the status for a
request with no_interrupt. The dwc3 driver needs to check the TRB status
associated with the request when reporting its status.

Note: this is only applicable to missed_isoc TRB completion status, but
the other status are also listed for completeness/documentation.

Fixes: 6d8a019614f3 ("usb: dwc3: gadget: check for Missed Isoc from event status")
Cc: <stable@vger.kernel.org>
Signed-off-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Link: https://lore.kernel.org/r/db2c80108286cfd108adb05bad52138b78d7c3a7.1650673655.git.Thinh.Nguyen@synopsys.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/usb/dwc3/gadget.c | 31 ++++++++++++++++++++++++++++++-
1 file changed, 30 insertions(+), 1 deletion(-)

--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -2415,6 +2415,7 @@ static int dwc3_gadget_ep_cleanup_comple
const struct dwc3_event_depevt *event,
struct dwc3_request *req, int status)
{
+ int request_status;
int ret;

if (req->request.num_mapped_sgs)
@@ -2444,7 +2445,35 @@ static int dwc3_gadget_ep_cleanup_comple
req->needs_extra_trb = false;
}

- dwc3_gadget_giveback(dep, req, status);
+ /*
+ * The event status only reflects the status of the TRB with IOC set.
+ * For the requests that don't set interrupt on completion, the driver
+ * needs to check and return the status of the completed TRBs associated
+ * with the request. Use the status of the last TRB of the request.
+ */
+ if (req->request.no_interrupt) {
+ struct dwc3_trb *trb;
+
+ trb = dwc3_ep_prev_trb(dep, dep->trb_dequeue);
+ switch (DWC3_TRB_SIZE_TRBSTS(trb->size)) {
+ case DWC3_TRBSTS_MISSED_ISOC:
+ /* Isoc endpoint only */
+ request_status = -EXDEV;
+ break;
+ case DWC3_TRB_STS_XFER_IN_PROG:
+ /* Applicable when End Transfer with ForceRM=0 */
+ case DWC3_TRBSTS_SETUP_PENDING:
+ /* Control endpoint only */
+ case DWC3_TRBSTS_OK:
+ default:
+ request_status = 0;
+ break;
+ }
+ } else {
+ request_status = status;
+ }
+
+ dwc3_gadget_giveback(dep, req, request_status);

out:
return ret;