Whats the thing with AMD Topaz generation?

[lumks]

Hey. I'm a bit confused about the topaz generation and the support on linux for them.
They seem to stay in all generations.

If you ask wikipedia, it's GCN 1.0 => https://en.wikipedia.org/wiki/List_o...ocessing_units (look for topaz)
if you ask x.org, it's 1.2 => https://www.x.org/wiki/RadeonFeature/#index5h2

Also on my laptop with standard archlinux it tries to load up radeon at first, until I blacklist it (because it will not load to GDM)
Could someone bring light to the darkness because it seems so weird.

[bridgman]

AFAIK Topaz was early VI (1.2) but I think the confusion comes from Topaz replacing an earlier SI part but keeping the same marketing name (eg M260).

I'm pretty sure the device IDs were different though, so it shouldn't be hard to tell which part you really have. If it's trying to load radeon then my first thought is that it probably is not a Topaz but the earlier (Oland/Hainan, I forget which is which).

Are you saying that if you blacklist radeon then it works properly with amdgpu ? That wasn't clear from your post.

[lumks]

Are you saying that if you blacklist radeon then it works properly with amdgpu ? That wasn't clear from your post.

Yes. Excatly.
The PCIID is 0380:1002:6900, as marketing name its called "Radeon 530".

So in Other words "Topaz" was for real a 1.0 generation and a 1.2 generation?

(BTW on Linux 4.14 and 4.15)

[bridgman]

Interesting, thanks.

I expect agd5f will come up with a better explanation, but at first glance it sounds as if we might have the same PCI ID appearing in both drivers. IF that is the case, then it might turn out to be required (ie if Topaz had same device ID as an earlier SI part, which seems unlikely but not impossible) or could be a typo.

[agd5f]

Yes. Excatly.
The PCIID is 0380:1002:6900, as marketing name its called "Radeon 530".

So in Other words "Topaz" was for real a 1.0 generation and a 1.2 generation?

(BTW on Linux 4.14 and 4.15)

Topaz is GCN 1.2. It has no display controllers or multi-media engines; just graphics/compute. It's designed for hybrid laptops. There are no overlapping pci ids; only amdgpu has code for it.

[bridgman]

There are no overlapping pci ids; only amdgpu has code for it.

That was my understanding as well... I just wasn't sure what might account for this behaviour that the OP observed:

Also on my laptop with standard archlinux it tries to load up radeon at first, until I blacklist it (because it will not load to GDM)

lumks , what is the CPU / iGPU on your system ? I didn't think OEMs paired Topaz with Kaveri/Kabini or older APUs (which default to radeon driver) but that's the only other "sensible" explanation I can think of.