[Nouveau] NVAC "No Signal"

[Karol Herbst]

2016-10-19 16:47 GMT+02:00 poma <pomidorabelisima at gmail.com>:
> On 18.10.2016 16:02, Karol Herbst wrote:
>> well, I just don't want that this fix breaks the same thing for other
>> users, that's why I am asking.
>>
>
> Affected device ID:
> https://github.com/skeggsb/nouveau/blob/master/drm/nouveau/nvkm/engine/device/pci.c#L1229
> can it be excluded from device->chipset case 0xac ?
>
> Care to create a patch?
> I'll test it.
>
>

You don't get why I try to say. We have to actually find out when to
apply this workaround, not to create some silly whitelist/blacklist.
It's the last option, we never want to actually use.

And even if we would have to create such lists, who tells us, that if
affects every GPU with your device id? Usually quirks are applied
depending on the sub-vendor-id and sub-device-id if actually required.

In the end we need something like this: If byte X in table Y is set in
the vbios or if bits A-B in reg Z in the MMIO space are set to
whatever, we have to apply that workaround.

In the end we should also wait until Ben replies, because he might
know the exact reasons why this workaround was actually needed.

We might have a GPU with the same chipset like yours and we might be
able to verify the issue