Re: Linux 4.2-rc1

[Shuah Khan <shuahkh@osg.samsung.com>]

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.

-- Shuah


-- 
Shuah Khan
Sr. Linux Kernel Developer
Open Source Innovation Group
Samsung Research America (Silicon Valley)
shuahkh@osg.samsung.com | (970) 217-8978