drm-kmod: AMD Ryzen Vega 8?

[Greg V]

On August 6, 2019 11:42:55 AM GMT+03:00, Grzegorz Junka <list1 at gjunka.com> wrote:
>
>On 06/08/2019 01:23, Greg V wrote:
>> On August 5, 2019 9:19:20 PM GMT+03:00, Grzegorz Junka
><list1 at gjunka.com> wrote:
>Does it give any clue why it works on my desktop?

No.

> I see a message about switching efifb to fb, is that the disabling you mean here?

That means you haven't disabled anything. If you set hw.syscons.disable=1 in the bootloader, you don't get display output before amdgpu loads, there's no switching, amdgpu's fb appears first because efifb was never there.

For most people so far, this workaround has been necessary.

>Should I expect any problems when switching to drm 5 later?

Who knows :) For me, 4.16 was worse – the module didn't even *load* successfully with efifb on. Though at that time I also upgraded from Polaris to Vega, and that also affects the behavior in some weird way.

>Do you mean that with drm 5 I will be able to use amdgpu instead of 
>i915? What about switching between the two graphics cards, which I 
>thought isn't supported?

Again: you don't *switch* and you can't use amdgpu *instead*. You have a modern laptop, not the (infamous) 2011 MacBook Pro. Google something like "muxless vs muxed gpu laptop" for more info.

Basically, only the Intel GPU has display outputs. You can't use amdgpu alone because that GPU does not have any display outputs. That GPU is only available for offloading. You just run heavy applications with DRI_PRIME=1 and they *render* on amdgpu, and the compositor running on the Intel GPU will just have access to that result and composite it as normal.