[PATCH v3 2/2] usb: dwc3: gadget: Don't set IMI for no_interrupt

[Thinh Nguyen <Thinh.Nguyen@synopsys.com>]

The gadget driver may have a certain expectation of how the request
completion flow should be from to its configuration. Make sure the
controller driver respect that. That is, don't set IMI (Interrupt on
Missed Isoc) when usb_request->no_interrupt is set. Also, the driver
should only set IMI to the last TRB of a chain.

Fixes: 72246da40f37 ("usb: Introduce DesignWare USB3 DRD Driver")
Cc: stable@vger.kernel.org
Signed-off-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
---
 Changes in v3:
 - Set IMI to only the last TRB of a chain
 Changes in v2:
 - None

 drivers/usb/dwc3/gadget.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 230b3c660054..5fe2d136dff5 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -1292,8 +1292,8 @@ static void dwc3_prepare_one_trb(struct dwc3_ep *dep,
 			trb->ctrl = DWC3_TRBCTL_ISOCHRONOUS;
 		}
 
-		/* always enable Interrupt on Missed ISOC */
-		trb->ctrl |= DWC3_TRB_CTRL_ISP_IMI;
+		if (!no_interrupt && !chain)
+			trb->ctrl |= DWC3_TRB_CTRL_ISP_IMI;
 		break;
 
 	case USB_ENDPOINT_XFER_BULK:
-- 
2.28.0