Re: [PATCH] usb: musb: Fix runtime PM race in musb_queue_resume_work

[Tony Lindgren]

* Paul Cercueil <paul@xxxxxxxxxxxxxxx> [200809 12:54]:
> musb_queue_resume_work() would call the provided callback if the runtime
> PM status was 'active'. Otherwise, it would enqueue the request if the
> hardware was still suspended (musb->is_runtime_suspended is true).
> 
> This causes a race with the runtime PM handlers, as it is possible to be
> in the case where the runtime PM status is not yet 'active', but the
> hardware has been awaken (PM resume function has been called).
> 
> When hitting the race, the resume work was not enqueued, which probably
> triggered other bugs further down the stack. For instance, a telnet
> connection on Ingenic SoCs would result in a 50/50 chance of a
> segmentation fault somewhere in the musb code.
> 
> Rework the code so that either we call the callback directly if
> (musb->is_runtime_suspended == 0), or enqueue the query otherwise.

Yes we should use is_runtime_suspended, thanks for fixing it.
Things still work for me so:

Reviewed-by: Tony Lindgren <tony@xxxxxxxxxxx>
Tested-by: Tony Lindgren <tony@xxxxxxxxxxx>