AMD Developers Discuss Better Switching Of Radeon/AMDGPU CIK Support

[phoronix]

Phoronix: AMD Developers Discuss Better Switching Of Radeon/AMDGPU CIK Support

Open-source AMD developers have been discussing in recent days how to better deal with the experimental support of GCN 1.1 "Sea Islands" (and GCN 1.0 "Southern Islands") support in AMDGPU and making it easier to enable while ensuring the Radeon DRM driver with its mature GCN 1.0/1.1 support doesn't interfere...

http://www.phoronix.com/scan.php?page=news_item&px=AMDGPU-Radeon-Switching-CIK

[andrei_me]

At first I read the headline as "switching Off" instead of "switching of", and was going to ask "WTF!?" haha

[chithanh]

Another possibility would be having a kernel command-line switch to toggle the desired driver.

I haven't tested it, but I think that

video=radeondrmfb:off

should do the trick already.

[eydee]

At first I read the headline as "switching Off" instead of "switching of", and was going to ask "WTF!?" haha

Will happen at some point. Can't stop the legacy train!

[schmidtbag]

Cool, sounds great to me.

[Detructor]

I may need some explanation here because I don't get it. Why can't they just put a UI frontend somewhere that allows a user to choose which driver should be used and then kill XServer and restart it? That's, basically, how (in theory) switching between NVidia and Intel GPUs has worked for years.

[artyom.h31]

I may need some explanation here because I don't get it. Why can't they just put a UI frontend somewhere that allows a user to choose which driver should be used and then kill XServer and restart it? That's, basically, how (in theory) switching between NVidia and Intel GPUs has worked for years.

Because Intel and Nvidia drivers access different hardware devices, so they can't interfere.

[Holograph]

I may need some explanation here because I don't get it. Why can't they just put a UI frontend somewhere that allows a user to choose which driver should be used and then kill XServer and restart it? That's, basically, how (in theory) switching between NVidia and Intel GPUs has worked for years.

The driver will actually grab your hardware and since we're talking about 2 drivers that might try to grab the same hardware, whichever tried second would fail. You need to prevent one of the two drivers from grabbing your GPU so the other one can get it.

I, on the other hand, want to know why AMDGPU keeps getting performance improvements, yet CIK has been such low priority. Considering when I bought my 290x, the driver situation was a mess with FGLRX coming to an end shortly after I got it. Radeon had problematic performance with Michael's 290 but AMD drags their feet so badly getting CIK enabled and made reasonably easy for an end user to activate, even though, again, my 290x was still pretty new and should get almost the same level of attention as Polaris given that the driver situation when it was released was so messed up. Really don't like to see AMD put products on the back burner so soon after their release.

But, hey, it's about time. Next, they need to take out the flag in the kernel config, so that distros cannot easily disable AMDGPU CIK functionality. I mean they could still patch source if they really wanted, but there is no need to make it easy for them to disable it.

[schmidtbag]

I may need some explanation here because I don't get it. Why can't they just put a UI frontend somewhere that allows a user to choose which driver should be used and then kill XServer and restart it? That's, basically, how (in theory) switching between NVidia and Intel GPUs has worked for years.

Well for one thing, this is extremely temporary (the feature is still considered experimental, after all). Kind of stupid to create a GUI tool for something that simply writes "blacklist radeonsi" in your /etc/modprobe.d/blacklist.conf. There's also the issue that not all distros work the same way.

[Detructor]

Well for one thing, this is extremely temporary (the feature is still considered experimental, after all). Kind of stupid to create a GUI tool for something that simply writes "blacklist radeonsi" in your /etc/modprobe.d/blacklist.conf. There's also the issue that not all distros work the same way.

uh. Okay. I was under the impression that they wanted something for a 'normal' user to work with. If they don't and blacklisting works...what is there to discuss?