usb: dwc3: Remove WARN_ON for device endpoint command timeouts
authorSelvarasu Ganesan <selvarasu.g@samsung.com>
Fri, 8 Aug 2025 12:53:05 +0000 (18:23 +0530)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Sun, 17 Aug 2025 10:14:11 +0000 (12:14 +0200)
commit45eae113dccaf8e502090ecf5b3d9e9b805add6f
tree9bbc266a3ada4332c94a8805010af2ff4de143c4
parenta3dc32c635bae0ae569f489e00de0e8f015bfc25
usb: dwc3: Remove WARN_ON for device endpoint command timeouts

This commit addresses a rarely observed endpoint command timeout
which causes kernel panic due to warn when 'panic_on_warn' is enabled
and unnecessary call trace prints when 'panic_on_warn' is disabled.
It is seen during fast software-controlled connect/disconnect testcases.
The following is one such endpoint command timeout that we observed:

1. Connect
   =======
->dwc3_thread_interrupt
 ->dwc3_ep0_interrupt
  ->configfs_composite_setup
   ->composite_setup
    ->usb_ep_queue
     ->dwc3_gadget_ep0_queue
      ->__dwc3_gadget_ep0_queue
       ->__dwc3_ep0_do_control_data
        ->dwc3_send_gadget_ep_cmd

2. Disconnect
   ==========
->dwc3_thread_interrupt
 ->dwc3_gadget_disconnect_interrupt
  ->dwc3_ep0_reset_state
   ->dwc3_ep0_end_control_data
    ->dwc3_send_gadget_ep_cmd

In the issue scenario, in Exynos platforms, we observed that control
transfers for the previous connect have not yet been completed and end
transfer command sent as a part of the disconnect sequence and
processing of USB_ENDPOINT_HALT feature request from the host timeout.
This maybe an expected scenario since the controller is processing EP
commands sent as a part of the previous connect. It maybe better to
remove WARN_ON in all places where device endpoint commands are sent to
avoid unnecessary kernel panic due to warn.

Cc: stable <stable@kernel.org>
Co-developed-by: Akash M <akash.m5@samsung.com>
Signed-off-by: Akash M <akash.m5@samsung.com>
Signed-off-by: Selvarasu Ganesan <selvarasu.g@samsung.com>
Acked-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://lore.kernel.org/r/20250808125315.1607-1-selvarasu.g@samsung.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/usb/dwc3/ep0.c
drivers/usb/dwc3/gadget.c