Re: Linux 4.2-rc1

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Thu, Jul 09, 2015 at 07:44:04AM -0600, Shuah Khan wrote:
> On 07/09/2015 07:10 AM, Shuah Khan wrote:
> > On 07/08/2015 09:17 PM, Linus Torvalds wrote:
> >> On Wed, Jul 8, 2015 at 5:58 PM, Ming Lei <ming.lei@canonical.com> wrote:
> >>> On Thu, Jul 9, 2015 at 1:29 AM, Linus Torvalds
> >>> <torvalds@linux-foundation.org> wrote:
> >>>> Also, it looks like you need to hold the "fw_lock" to even look at
> >>>> that pointer, since the buffer can get reallocated etc.
> >>>
> >>> Yes, the above code with holding 'fw_lock' is right fix for the issue since
> >>> sysfs read can happen anytime, and there is one race between firmware
> >>> request abort and reading uevent of sysfs.
> >>
> >> So if fw_priv->buf is NULL, what should we do?
> >>
> >> Should we skip the TIMEOUT= and ASYNC= fields too?
> >>
> >> Something like the attached, perhaps?
> >>
> >> Shuah, how reproducible is this? Does this (completely untested) patch
> >> make any difference?
> >>
> > 
> > Happened both times I booted 4.2-rc1 up, so I would say 100% so far.
> > I will test with your patch and report results.
> > 
> 
> Yes. This patch fixed the problem.

That's great, but what changed recently to cause this problem to happen?
Any chance you can bisect to the problem commit?

thanks,

greg k-h