[PATCH 0/1][F/H] Fix usb hub failure caused by short power-on-good delay

Chris Chiu chris.chiu at canonical.com
Thu Aug 12 13:35:11 UTC 2021

BugLink: https://bugs.launchpad.net/bugs/1939638

The USB devices (keyboard, storage...) are failed to be detected when connecting to the problematic root hubs which need longer PowerOn-to-PowerGood delay than it claims in the hub descriptor. It's caused by the upstream fix 90d28fb53d4a ("usb: core: reduce power-on-good delay time of root hub").

Reverting the upstream fix until a formal fix been placed.

[Test Case]
1. Plug the USB device to the ports of problematic root hub.
2. Power on the machine.
3. Check if the USB device can work or not after boot.

[Regression Potential]
Low. The longer delay is proven safe in old kernels.

Chris Chiu (1):
  Revert "usb: core: reduce power-on-good delay time of root hub"

 drivers/usb/core/hub.h | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)


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