Re: [REGRESSION] media: cx23885 broken by commit 453afdd "[media] cx23885: convert to vb2"

[Hans Verkuil <hverkuil@xs4all.nl>]

Hi Raimonds,

On 01/11/2015 10:33 AM, Raimonds Cicans wrote:
> Hello.
> 
> I contacted you because I am hit by regression caused by your commit:
> 453afdd "[media] cx23885: convert to vb2"
> 
> 
> My system:
> AMD Athlon(tm) II X2 240e Processor on Asus M5A97 LE R2.0 motherboard
> TBS6981 card (Dual DVB-S/S2 PCIe receiver, cx23885 in kernel driver)
> 
> After upgrade from kernel 3.13.10 (do not have commit) to 3.17.7
> (have commit) I started receiving following IOMMU related messages:
> 
> 1)
> AMD-Vi: Event logged [IO_PAGE_FAULT device=0a:00.0 domain=0x001d 
> address=0x000000000637c000 flags=0x0000]
> 
> where device=0a:00.0 is TBS6981 card

As far as I can tell this has nothing to do with the cx23885 driver but is
a bug in the amd iommu/BIOS. See e.g.:

https://bbs.archlinux.org/viewtopic.php?pid=1309055

I managed to reproduce the Intel equivalent if I enable CONFIG_IOMMU_SUPPORT.

Most likely due to broken BIOS/ACPI/whatever information that's read by the
kernel. I would recommend disabling this kernel option.

Regards,

	Hans

> 
> sometimes this message was followed by storm of following messages:
> cx23885[0]: mpeg risc op code error
> ...