[PATCH 0/7] usb: dwc3: gadget: Fix No Resource after End Transfer

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

The dwc3 driver can issue a Start Transfer command while a previous End
Transfer command on the same endpoint has not completed. The controller then
rejects it with "No Resource", and the endpoint stays unusable.

This happens in two cases:
 * On ep disable, the End Transfer command is issued without interrupt and its
   completion isn't tracked. A quick re-enable or queue to the endpoint can
   race with it.
 * A timed out End Transfer is treated as done, and the endpoint resource index
   is lost.

This series tracks the End Transfer completion on ep disable and on timeout. It
also avoids an unneeded no-op Start Transfer on non-stream endpoints, and
rejects requests queued to an endpoint that is being disabled. If the End
Transfer never completes, the driver recovers through the existing error
recovery, and stale endpoint flags are reset on controller start.

Thanks to Selvarasu for reporting and debugging the issue.

Link: https://lore.kernel.org/linux-usb/20260227121236.963-1-selvarasu.g@samsung.com/



Thinh Nguyen (7):
  usb: dwc3: gadget: Reject requests to a disabled endpoint
  usb: dwc3: gadget: Track a timed out End Transfer
  usb: dwc3: gadget: Clear delayed stop on End Transfer completion
  usb: dwc3: gadget: Issue no-op Start Transfer only for stream endpoints
  usb: dwc3: gadget: Wait for End Transfer completion on ep disable
  usb: dwc3: gadget: Reset endpoint flags on controller start
  usb: dwc3: gadget: Recover from End Transfer timeout

 drivers/usb/dwc3/core.h   |   4 +-
 drivers/usb/dwc3/ep0.c    |   2 +-
 drivers/usb/dwc3/gadget.c | 160 +++++++++++++++++++++++++-------------
 3 files changed, 109 insertions(+), 57 deletions(-)


base-commit: bdf12cde30830d46a8ef1ba93986356f1164b4f1
-- 
2.53.0