usb: dwc3: gadget: Don't set IMI for no_interrupt

commit 308c316d16cbad99bb834767382baa693ac42169 upstream.

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>
Reviewed-by: Jeff Vanhoof <jdv1029@gmail.com>
Tested-by: Jeff Vanhoof <jdv1029@gmail.com>
Link: https://lore.kernel.org/r/ced336c84434571340c07994e3667a0ee284fefe.1666735451.git.Thinh.Nguyen@synopsys.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index e38cee8..c38418b 100644 (file)
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -1263,8 +1263,8 @@ 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: