[PATCH 3.16.y-ckt 035/185] usb: dwc3: gadget: return error if command sent to DGCMD register fails

[Luis Henriques]

3.16.7-ckt15 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Subbaraya Sundeep Bhatta <subbaraya.sundeep.bhatta at xilinx.com>

commit 891b1dc022955d36cf4c0f42d383226a930db7ed upstream.

We need to return error to caller if command is not sent to
controller succesfully.

Signed-off-by: Subbaraya Sundeep Bhatta <sbhatta at xilinx.com>
Fixes: b09bb64239c8 (usb: dwc3: gadget: implement Global Command support)
Signed-off-by: Felipe Balbi <balbi at ti.com>
[ luis: backported to 3.16: adjusted context ]
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/usb/dwc3/gadget.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index c24c0bb7f6f3..0c4a7aba42cb 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -376,6 +376,8 @@ int dwc3_send_gadget_generic_command(struct dwc3 *dwc, int cmd, u32 param)
 		if (!(reg & DWC3_DGCMD_CMDACT)) {
 			dev_vdbg(dwc->dev, "Command Complete --> %d\n",
 					DWC3_DGCMD_STATUS(reg));
+			if (DWC3_DGCMD_STATUS(reg))
+				return -EINVAL;
 			return 0;
 		}