From: Hans Verkuil <hverkuil@xs4all.nl>
To: Shuah Khan <shuahkh@osg.samsung.com>,
"mauro Carvalho Chehab (m.chehab@samsung.com)"
<m.chehab@samsung.com>,
Linux Media Mailing List <linux-media@vger.kernel.org>
Subject: Re: au0828_init_tuner() called without dev lock held
Date: Mon, 22 Sep 2014 18:37:18 +0200 [thread overview]
Message-ID: <5420503E.7010608@xs4all.nl> (raw)
In-Reply-To: <54204ECC.7070806@osg.samsung.com>
On 09/22/2014 06:31 PM, Shuah Khan wrote:
> Hi Hans and Mauro,
>
> While I was making changes for media token work, I noticed there are
> several places au0828_init_tuner() gets called without holding dev lock.
au0828 sets the lock pointer in struct video_device to the dev lock.
That means that all v4l2 ioctl calls are serialized in v4l2_ioctl()
in v4l2-dev.c. So these calls *do* hold the device lock.
Not au0828_v4l2_resume() though, that's not an ioctl op.
Regards,
Hans
>
> vidioc_s_std(), vidioc_g_tuner(), vidioc_s_tuner(), vidioc_streamon()
> au0828_v4l2_resume()
>
> Some of these might be intended since au0828_init_tuner() invokes
> s_std. All of these changes including the au0828_init_tuner() itself
> were added in ea86968fb91471493ccac7d8f2a65bc65db6803b
>
> au0828_v4l2_resume() also does this and this one for sure needs fixing
> very likely. I am not sure about the others. Thoughts??
>
> -- Shuah
>
next prev parent reply other threads:[~2014-09-22 16:37 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-22 16:31 au0828_init_tuner() called without dev lock held Shuah Khan
2014-09-22 16:37 ` Hans Verkuil [this message]
2014-09-22 16:40 ` Shuah Khan
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