[PATCH 1/1] usb: dwc3: fix Clear Stall EP command failure

[Lu Baolu <baolu.lu@linux.intel.com>]

Commit 50c763f8c1bac ("usb: dwc3: Set the ClearPendIN bit on Clear
Stall EP command") sets ClearPendIN bit for all IN endpoints in
v2.60a+ cores no matter which speed mode they're in. This causes
Clear Stall EP command failing on some Intel devices.

In page 539 of 2.60a specification, it says:

"When issuing Clear Stall command for IN endpoints in SuperSpeed
mode, the software must set the "ClearPendIN" bit to '1' to
clear any pending IN transcations, so that the device does not
expect any ACK TP from the host for the data sent earlier."

It's obviously that we only need to apply this rule to those IN
endpoints in SuperSpeed mode.

Fixes: 50c763f8c1bac ("usb: dwc3: Set the ClearPendIN bit on Clear Stall EP command")
Cc: stable@vger.kernel.org # 4.7+
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 drivers/usb/dwc3/gadget.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 7a8d3d8..f1858d6 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -348,7 +348,8 @@ static int dwc3_send_clear_stall_ep_cmd(struct dwc3_ep *dep)
 	 * IN transfers due to a mishandled error condition. Synopsys
 	 * STAR 9000614252.
 	 */
-	if (dep->direction && (dwc->revision >= DWC3_REVISION_260A))
+	if (dep->direction && (dwc->revision >= DWC3_REVISION_260A) &&
+	    (dwc->maximum_speed >= USB_SPEED_SUPER))
 		cmd |= DWC3_DEPCMD_CLEARPENDIN;
 
 	memset(&params, 0, sizeof(params));
-- 
2.1.4