Re: [Xen-devel] Xen 4.2.0-rc4 issues with DVB tuner

[Javier Marcet <jmarcet@xxxxxxxxx>]

On Mon, Sep 17, 2012 at 4:28 PM, Konrad Rzeszutek Wilk
<konrad@xxxxxxxxxx> wrote:

>> >> This last point is a showstopper for me and I donÂt know where the
>> >> problem might come from. The cx23885 module (which my tuners use)
>> >> loads fine, as do the devices under /dev/dvb. Upon tuning a channel,
>> >> however, there is not data received.
>> >>
>> >> Does anyone have the slightest idea what might be causing this?
>> >
>> > Are there any warnings or such being printed? Are the interrupts 
>> > increasing?
>> > Does lspci show anything 'disabled' in the guest?
>>
>> You have misunderstood me. I was trying to access the dvb tuners from the 
>> dom0.
>
> Ah.
>>
>> Using kvm I have sucessfully passthrough a sata controller, but have some 
>> issues
>> passin through the dvb tuner.
>>
>> >> I wonder whether it would work within a DomU with the PCIe tuner
>> >> passed through.
>> >
>> > I've a 4 channel security card passed in and it works nicely. The
>> > trick is that you need 'iommu=soft' on the domU command line.
>>
>> All right. But is it normal that it does not work under the dom0?
>
> No. PV domU and PV dom0 are pretty much the same in the way of handling
> interrupts, ports, etc.

Just as I guessed.

> If you crank up the debug level of the kernel (debug loglevel=8) and
> of the driver do you get anything obvious? What about the questions
> I've asked?

So far I haven't found anything worth mentioning.

All pci devices are enabled, interrupts look normal and there isn't any
kind of warning or error message. The only thing you notice is that
the tuner produces nearly no data. I say nearly because you get some
bytes, albeit nothing like the several megabits per second it should output.

I'll try increasing the debug level and report back.

By the way, that problem I had about the cpu capabilities is not Xen's fault,
it is a bug within libvirt.


-- 
Javier Marcet <jmarcet@xxxxxxxxx>

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