Messages in this thread | | | Subject | Re: [RE-RESEND PATCH 1/4] usb: musb: Fix runtime PM race in musb_queue_resume_work | From | Sergei Shtylyov <> | Date | Sat, 23 Jan 2021 19:41:48 +0300 |
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On 1/23/21 5:24 PM, Paul Cercueil wrote:
> 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).
Awakened. :-)
> 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. > > Fixes: ea2f35c01d5e ("usb: musb: Fix sleeping function called from invalid context for hdrc glue") > Cc: stable@vger.kernel.org # v4.9+ > Signed-off-by: Paul Cercueil <paul@crapouillou.net> > Reviewed-by: Tony Lindgren <tony@atomide.com> > Tested-by: Tony Lindgren <tony@atomide.com> [...]
MBR, Sergei
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