[PATCH 4.9 100/134] usb: dwc3: gadget: Fix dep->interval for fullspeed interrupt

[Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>]

From: Thinh Nguyen <Thinh.Nguyen@xxxxxxxxxxxx>

commit 4b049f55ed95cd889bcdb3034fd75e1f01852b38 upstream.

The dep->interval captures the number of frames/microframes per interval
from bInterval. Fullspeed interrupt endpoint bInterval is the number of
frames per interval and not 2^(bInterval - 1). So fix it here. This
change is only for debugging purpose and should not affect the interrupt
endpoint operation.

Fixes: 72246da40f37 ("usb: Introduce DesignWare USB3 DRD Driver")
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Thinh Nguyen <Thinh.Nguyen@xxxxxxxxxxxx>
Link: https://lore.kernel.org/r/1263b563dedc4ab8b0fb854fba06ce4bc56bd495.1612820995.git.Thinh.Nguyen@xxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/usb/dwc3/gadget.c |    7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -538,8 +538,13 @@ static int dwc3_gadget_set_ep_config(str
 		if (dwc->gadget.speed == USB_SPEED_FULL)
 			bInterval_m1 = 0;
 
+		if (usb_endpoint_type(desc) == USB_ENDPOINT_XFER_INT &&
+		    dwc->gadget.speed == USB_SPEED_FULL)
+			dep->interval = desc->bInterval;
+		else
+			dep->interval = 1 << (desc->bInterval - 1);
+
 		params.param1 |= DWC3_DEPCFG_BINTERVAL_M1(bInterval_m1);
-		dep->interval = 1 << (desc->bInterval - 1);
 	}
 
 	return dwc3_send_gadget_ep_cmd(dep, DWC3_DEPCMD_SETEPCONFIG, &params);