usb: chipidea: udc: otg_set_peripheral is useless for some chipidea users

It is useless at below cases:
- If we implement both usb host and device at chipidea driver.
- If we don't need phy->otg.

Tested-by: Marek Vasut <marex@denx.de>
Signed-off-by: Peter Chen <peter.chen@freescale.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 6 insertions, 1 deletions

diff --git a/drivers/usb/chipidea/udc.c b/drivers/usb/chipidea/udc.c
index e475fcda1d68..116c76203884 100644
--- a/drivers/usb/chipidea/udc.c
+++ b/drivers/usb/chipidea/udc.c
@@ -1805,7 +1805,12 @@ static int udc_start(struct ci_hdrc *ci)
         if (ci->transceiver) {
                 retval = otg_set_peripheral(ci->transceiver->otg,
                                                 &ci->gadget);
-                if (retval)
+                /*
+                 * If we implement all USB functions using chipidea drivers,
+                 * it doesn't need to call above API, meanwhile, if we only
+                 * use gadget function, calling above API is useless.
+                 */
+                if (retval && retval != -ENOTSUPP)
                         goto put_transceiver;
         }