nouveau optimus HDMI audio support

[Dave Airlie]

On Mon, Oct 7, 2013 at 10:30 AM, Jethro Beekman <dri-devel at jbeekman.nl> wrote:
>
>
> On 06-10-13 16:48, Dave Airlie wrote:
>> On Mon, Oct 7, 2013 at 8:45 AM, Jethro Beekman <dri-devel at jbeekman.nl> wrote:
>>> On 06-10-13 15:00, Dave Airlie wrote:
>>>> On Mon, Oct 7, 2013 at 7:04 AM, Jethro Beekman <dri-devel at jbeekman.nl> wrote:
>>>>> Even with Dave Airlie's recent patch set (
>>>>> http://lists.freedesktop.org/archives/dri-devel/2013-August/042854.html ), I'm
>>>>> still having trouble getting HDMI audio to work on my optimus laptop. I'm
>>>>> running Linux 3.12.0-rc3 on a Lenovo ThinkPad T420s. When I set my BIOS graphics
>>>>> option to 'Discrete', I get the following two devices in lspci:
>>>>>
>>>>> 01:00.0 VGA compatible controller: NVIDIA Corporation GF119 [Quadro NVS 4200M]
>>>>> (rev a1)
>>>>> 01:00.1 Audio device: NVIDIA Corporation HDMI Audio stub (rev a1)
>>>>>
>>>>> When I set the option to 'Optimus', the 01:00.1 device disappears completely.
>>>>> This is dmesg when loading nouveau in the Optimus configuration:
>>>>>
>>>>> pci 0000:01:00.0: optimus capabilities: enabled, status dynamic power, hda bios
>>>>> codec supported
>>>>> VGA switcheroo: detected Optimus DSM method \_SB_.PCI0.PEG_.VID_ handle
>>>>> [drm] hdmi device  not found 1 0 1
>>>>>
>>>>> I modified snd-hda-intel to report which devices it's probing, this is the only
>>>>> one that shows up:
>>>>>
>>>>> hda-intel: azx_probe: 0000:00:1b.0
>>>>>
>>>>> Any ideas what's going on?
>>>>
>>>> Wierd, I wonder does it route the codecs via the other device, though
>>>> I can't remember how to see what codecs are available.
>>>
>>> /proc/asound/card0/ lists only a single codec which is for analog i/o.
>>>
>>>> The other thing would be to try and hack on the hdmi stub using the
>>>> code in my patches that does it after s/r but do it at startup.
>>>
>>> Could you be a little more specific? I tried moving nouveau_get_hdmi_dev() later
>>> so we have drm->device setup and then adding the 'do magic' nv_mask() call
>>> before that. That's either not working or something more needs to happen to make
>>> it work.
>>
>> yeah doing the do magic might not work though since Linux would have to rescan
>> the PCI bus for the hdmi driver to detect it, I wonder can you poke
>> registers from grub,
>> or maybe geneate some sort of pci hotplug even so the other layers notice.
>
> I added this, copied from the handler for /sys/bus/pci/rescan:
>
> struct pci_bus *b = NULL;
>
> while ((b = pci_find_next_bus(b)) != NULL)
>         pci_rescan_bus(b);
>
> No luck... Also tried adding a specific pci_scan_slot().
>
> How did you find out about the magic register? Are we sure that it's supposed to
> work on my device?

No idea, magic is magic for a reason. You can read it back when you
are booted discrete and see if poking it makes hdmi device disappear.

Dave.