Re: [RFT PATCH v3 1/1] usb: hub: Fix flushing of delayed work used for post resume purposes

[Greg KH <gregkh@linuxfoundation.org>]

On Fri, Jun 27, 2025 at 07:43:48PM +0300, Mathias Nyman wrote:
> Delayed work that prevents USB3 hubs from runtime-suspending too early
> needed to be flushed in hub_quiesce() to resolve issues detected on
> QC SC8280XP CRD board during suspend resume testing.
> 
> This flushing did however trigger new issues on Raspberry Pi 3B+, which
> doesn't have USB3 ports, and doesn't queue any post resume delayed work.
> 
> The flushed 'hub->init_work' item is used for several purposes, and
> is originally initialized with a 'NULL' work function. The work function
> is also changed on the fly, which may contribute to the issue.
> 
> Solve this by creating a dedicated delayed work item for post resume work,
> and flush that delayed work in hub_quiesce()
> 
> Cc: stable@kernel.org
> Fixes: a49e1e2e785f ("usb: hub: Fix flushing and scheduling of delayed work that tunes runtime pm")
> Reported-by: Mark Brown <broonie@kernel.org>
> Closes: https://lore.kernel.org/linux-usb/aF5rNp1l0LWITnEB@finisterre.sirena.org.uk
> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
> ---
> v3:
>  - Rebase on top of a49e1e2e785f ("usb: hub: Fix flushing and scheduling of delayed work that tunes runtime pm")
>  - Rewrite commit message 
> 
> v2:
>  - Add and use dedicated delayed work struct for post resume work
>  - Add commit message section about dedicated work

This seems to work, want me to take this, or are you going to submit
another one?  I'll hold off on sending the pull request to Linus for
-rc4 because of this.

thanks,

greg k-h