Re: BUG: Freeze upon loading bttv module

Hans Verkuil
2013-11-09T23:00:59Z

Hi Lorenz,

On 11/09/2013 05:18 PM, Lorenz Röhrl wrote:
> Hi,
>
> i'm having problems loading the bttv-module for my bt878 based DVB-T
> card: my system just freezes. Magic-Syskeys also won't work then.
> With kernel 3.9.0 this worked just fine. Versions 3.10, 3.11 and 3.12
> won't work.
>
> Last messages on screen with 3.12 upon booting/loading the module is:
> http://abload.de/img/bttv_freezeqxdn2.png
>
> With kernel 3.9 i get an additional line on module loading and the
> device works fine:
> [ 1.895037] bttv: 0: add subdevice "dvb0"
>
> I traced the problem, it dies somewhere in v4l2_ctrl_handler_setup on
> line 4169
> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/drivers/media/pci/bt8xx/bttv-driver.c#n4169

Can you try this patch? I'm not 100% but I think this might be the cause of
the problem.

diff --git a/drivers/media/pci/bt8xx/bttv-driver.c b/drivers/media/pci/bt8xx/bttv-driver.c
index c6532de..4f0aaa5 100644
--- a/drivers/media/pci/bt8xx/bttv-driver.c
+++ b/drivers/media/pci/bt8xx/bttv-driver.c
@@ -4182,7 +4182,8 @@ static int bttv_probe(struct pci_dev *dev, const struct pci_device_id *pci_id)
}
btv->std = V4L2_STD_PAL;
init_irqreg(btv);
- v4l2_ctrl_handler_setup(hdl);
+ if (!bttv_tvcards[btv->c.type].no_video)
+ v4l2_ctrl_handler_setup(hdl);
if (hdl->error) {
result = hdl->error;
goto fail2;

Regards,

Hans

>
> lspci output from kernel 3.9:
> [...]
> 04:01.0 Multimedia video controller: Brooktree Corporation Bt878 Video
> Capture (rev 11)
> Subsystem: Twinhan Technology Co. Ltd VisionPlus DVB card
> Flags: bus master, medium devsel, latency 32, IRQ 16
> Memory at f0401000 (32-bit, prefetchable) [size=4K]
> Capabilities: [44] Vital Product Data
> Capabilities: [4c] Power Management version 2
> Kernel driver in use: bttv
> Kernel modules: bttv
>
> 04:01.1 Multimedia controller: Brooktree Corporation Bt878 Audio Capture
> (rev 11)
> Subsystem: Twinhan Technology Co. Ltd VisionPlus DVB Card
> Flags: bus master, medium devsel, latency 32, IRQ 16
> Memory at f0400000 (32-bit, prefetchable) [size=4K]
> Capabilities: [44] Vital Product Data
> Capabilities: [4c] Power Management version 2
> Kernel driver in use: bt878
> Kernel modules: bt878
>
>
>
> Please CC me as i'm not subscribed to the list.
>
> Thanks!
>
> - Lorenz
> --
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