When servicing a transfer completion event, the dwc3 driver will reclaim TRBs of started requests up to the request associated with the interrupt event. Currently we don't check for interrupt due to missed isoc, and the driver may attempt to reclaim TRBs beyond the associated event. This causes invalid memory access when the hardware still owns the TRB. If there's a missed isoc TRB with IMI (interrupt on missed isoc), make sure to stop servicing further.

Note that only the last TRB of chained TRBs has its status updated with missed isoc.

Fixes: 72246da40f37 ("usb: Introduce DesignWare USB3 DRD Driver") Cc: stable@vger.kernel.org Reported-by: Jeff Vanhoof jdv1029@gmail.com Reported-by: Dan Vacura w36195@motorola.com Signed-off-by: Thinh Nguyen Thinh.Nguyen@synopsys.com --- Changes in v3: - None Changes in v2: - No need to check for CHN=0 since only the last TRB has its status updated to missed isoc

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

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index dd8ecbe61bec..230b3c660054 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -3248,6 +3248,10 @@ static int dwc3_gadget_ep_reclaim_completed_trb(struct dwc3_ep *dep, if (event->status & DEPEVT_STATUS_SHORT && !chain) return 1;

+ if ((trb->ctrl & DWC3_TRB_CTRL_ISP_IMI) && + DWC3_TRB_SIZE_TRBSTS(trb->size) == DWC3_TRBSTS_MISSED_ISOC) + return 1; + if ((trb->ctrl & DWC3_TRB_CTRL_IOC) || (trb->ctrl & DWC3_TRB_CTRL_LST)) return 1;

On Tue, Oct 25, 2022 at 03:10:20PM -0700, Thinh Nguyen wrote:

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

No new issues seen with these changes. Changes look good to me.

Reviewed-by: Jeff Vanhoof jdv1029@gmail.com Tested-by: Jeff Vanhoof jdv1029@gmail.com

Regards, Jeff