[SRU][F/I][PATCH 0/4] Fix USB devices not being detected at boot

[Kleber Souza]

On 07.04.22 22:00, Luke Nowakowski-Krijger wrote:
> [SRU Justification]
> 
> [Impact]
> There are users with certain intel xHCI controllers that are
> experiencing problems with USB devices not being detected at boot.
> 
> This is because when the primary roothub is registered, device
> enumeration happens before xHC is running and leads to devices not being
> detected. This results in the error that looks something like
> 'usb usb1-port3: couldn't allocate usb_device'.
> 
> [Fix]
> Register both root hubs along with the secondary hcd for xhci.
> 
> This original fix was reverted upstream due to regressions that occured due to
> racing that happened when both roothubs were registered simultaneously.
> However with those fixes being addressed in commits
> ("usb: hub: Fix usb enumeration issue due to address0 race")
> ("usb: hub: Fix locking issues with address0_mutex")
> the maintainers have stated that they will be reintroducing this commit.
> So lets reintroduce it here to fix the issues that users are
> experiencing.
> 
> [Test Case]
> Confirmed by Chris Chiu that this issue exists on similiar hardware
> reported by the users and that reverting these reverts fixes the issue
> showing no signs of 'couldn't allocate usb_device' and with USB devices
> available after boot.
> 
> [Regression Potential]
> Should be low now that we carry the fixes that seemed to be caused by
> this patch series.
> 
> Luke Nowakowski-Krijger (2):
>    UBUNTU: SAUCE: Revert "Revert "xhci: Set HCD flag to defer primary
>      roothub registration""
>    UBUNTU: SAUCE: Revert "Revert "usb: core: hcd: Add support for
>      deferring roothub registration""
> 
>   drivers/usb/core/hcd.c  | 29 +++++++++++++++++++++++------
>   drivers/usb/host/xhci.c |  1 +
>   include/linux/usb/hcd.h |  2 ++
>   3 files changed, 26 insertions(+), 6 deletions(-)
> 

Hi Luke,

Is this fix also needed for Jammy and unstable?