Re: Re: PCI passthrough stopped working, brainache!

[Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>]

On Wed, Oct 12, 2011 at 10:36:12PM +0100, Andy Burns wrote:
> On 12 October 2011 09:01, Andy Burns <xen.lists@burns.me.uk> wrote:
> 
> > Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> wrote:
> >
> >> So it works now right?
> >
> > No.

<Grumble>
> >
> > I think I remember what was the test I did before the boot that
> > started working again
> 
> I didn't get much time to test this today ... reverted to same Xen and
> kernel versions that worked briefly last night.
> 
> I discovered that (despite what I answered earlier) the PCI tuners
> don't work in dom0 under Xen, they only work if the dom0 is booted  as
> baremetal.
> 
> If I reboot from dom0 from baremetal with the PCI cards working into
> Xen without powering off, it doesn't "magically" leave the PCI cards
> in a state that allows them to work in the domU.
> 
> The thing which *seemed* to put it into a good mood last night was
> booting dom0 with serial console and the domU with the PIC cards but
> without the PCIe card, but that made no difference today.
> 
> I'm beginning to follow Konrad's thoughts that there is a specific
> sequence of events, that persists in hardware state across soft
> reboots, occasionally ending up with functioning PCI cards.
> 
> Is the fact that the PCI cards fail in dom0 under Xen a hint?  Any
> debugging I can do with the tuners from the dom0 rather than the domU
> with passthrough?

That is. That would imply it is not the PCI passthrough code (good!).
It is something related to the driver (as I presume your network card
works in that box). Perhaps it is the VM_IO bug that sometimes creeps
up.. Can you give me the lsmod output please? I want to see which
drivers are loaded for this TV card and I can dig a bit in the
driver to see if there is something fishy.

I saw something about I2C, is there a knob in the driver to _not_
use I2C?