Radeon Driver Gets Golden Registers In Linux 3.10

[agd5f]

They are the recommended register settings from the hw team for a variety of blocks. It may help with strange behavior or bugs on certain cards. We are already setting a lot of these registers in the gpu init sequences in the driver. In a lot of cases, the default power on values are fine which is why the existing driver works fine. In many cases the golden setting are just optimized settings.

[Drago]

Some register are initialized by video bios not atombios, and they are initialized one time at boot. Now that d3 cold is becoming a reality we will need to reinitialize those register when coming out of d3 cold, and there might other case where we will need to reinitialize them.

What is "d3 cold"?

[glisse]

Shouldn't "need to" be replaced by "should" ? Or if it was really "need", how come everything has been working fine without those golden registers ? Anyone from AMD would dare to comment on that ? Thanks!

Some register are initialized by video bios not atombios, and they are initialized one time at boot. Now that d3 cold is becoming a reality we will need to reinitialize those register when coming out of d3 cold, and there might other case where we will need to reinitialize them.

[wargames]

According to this Git commit, golden arrays for AMD Radeon graphics processors come down to arrays of register settings that need to be initialized at the ASIC (GPU) start-up.

The sets of new "golden" registers to initialize at start time were added for the Radeon HD 4000 (R7xx), Radeon HD 5000 (Evergreen), Radeon HD 6000 (Cayman / Northern Islands), and the Radeon HD 7000 (Southern Islands) series.

Shouldn't "need to" be replaced by "should" ? Or if it was really "need", how come everything has been working fine without those golden registers ? Anyone from AMD would dare to comment on that ? Thanks!

[Ragas]

I am pretty sure Michael himself didn't understand what golden registers are.

Here is what I gathered.

Golden registers are arrays of register settings from the hw team that need to be initialized at asic startup.

http://cgit.freedesktop.org/~agd5f/linux/commit/?h=drm-next-3.10-2&id=2e1b65f98bcaea6544d8781c3b34c631fcebe29a

Also it seems to be nothing incredibly new, since there are golden register commits that were one jear ago.

http://people.freedesktop.org/~agd5f/backendmap/0003-drm-radeon-kms-r600-program-golden-registers-on-init.patch

[V10lator]

Unless of course atombios etc does this.

If it does it, why does the driver now have to do it, too?

Or the defaults are sane enough that the GPU comes up, albeit underpowerd and underfeatured?

Static power management always worked fine for me. The GPU had always the speed and voltage it should have. Also what features should be missing without golden registers?

[oliver]

No as the GPU runs without this new thing, too, or where are all these "I have a black screen cause of no golden registers" bug reports?

Unless of course atombios etc does this. Or the defaults are sane enough that the GPU comes up, albeit underpowerd and underfeatured?

[V10lator]

...Without those setup right, the GPU can't run...

Make sense?

No as the GPU runs without this new thing, too, or where are all these "I have a black screen cause of no golden registers" bug reports?

[oliver]

I'm pretty sure its the initial set of registers that need to be setup so that the GPU can start to do something.

Think of those registers as things like setting the clocks right, voltage correct, dividers etc. Without those setup right, the GPU can't run. I'm sure there's more technical things being done as well.

Make sense?

[fa5hion]

Can a Dev weigh in more on "Golden Registers" ? It sounds important but Im not really grasping the concept from michael's summary

Something to do with power management?