On 03/03/2016 01:39 PM, Olli Salonen wrote:
> Hello Shuah,
>
> This patch seems to cause issues with my setup. Basically, when I try
> to tune to a channel, I get an oops. I'm using TechnoTrend CT2-4650
> PCIe DVB-T tuner (cx23885).
>
> Here's the oops:
>
> [ 548.443272] BUG: unable to handle kernel NULL pointer dereference
> at 0000000000000010
> [ 548.452036] IP: [<ffffffffc020ffc9>]
> v4l_vb2q_enable_media_source+0x9/0x50 [videodev]
Hi Olli,
Will you be able to use gdb and tell me which source line is
the cause? Could you give this following patch a try and if it
fixes the problem?
thanks,
-- Shuah
diff --git a/drivers/media/v4l2-core/v4l2-mc.c b/drivers/media/v4l2-core/v4l2-mc.c
index 643686d..a39a3cd 100644
--- a/drivers/media/v4l2-core/v4l2-mc.c
+++ b/drivers/media/v4l2-core/v4l2-mc.c
@@ -214,6 +214,8 @@ int v4l_vb2q_enable_media_source(struct vb2_queue *q)
{
struct v4l2_fh *fh = q->owner;
- return v4l_enable_media_source(fh->vdev);
+ if (fh && fh->vdev)
+ return v4l_enable_media_source(fh->vdev);
+ return 0;
}
EXPORT_SYMBOL_GPL(v4l_vb2q_enable_media_source);
shuah@anduin:~/lkml/linux_media_feb27_2016$ git diff > temp.diff
shuah@anduin:~/lkml/linux_media_feb27_2016$ cat temp.diff
diff --git a/drivers/media/v4l2-core/v4l2-mc.c b/drivers/media/v4l2-core/v4l2-mc.c
index 643686d..a39a3cd 100644
--- a/drivers/media/v4l2-core/v4l2-mc.c
+++ b/drivers/media/v4l2-core/v4l2-mc.c
@@ -214,6 +214,8 @@ int v4l_vb2q_enable_media_source(struct vb2_queue *q)
{
struct v4l2_fh *fh = q->owner;
- return v4l_enable_media_source(fh->vdev);
+ if (fh && fh->vdev)
+ return v4l_enable_media_source(fh->vdev);
+ return 0;
}
EXPORT_SYMBOL_GPL(v4l_vb2q_enable_media_source);
--
Shuah Khan
Sr. Linux Kernel Developer
Open Source Innovation Group
Samsung Research America (Silicon Valley)
shuahkh@xxxxxxxxxxxxxxx | (970) 217-8978
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