Intel & Radeon DRM Drivers Get Last Minute 3.15 Fixes

[phoronix]

Phoronix: Intel & Radeon DRM Drivers Get Last Minute 3.15 Fixes

Fallout from the many changes introduced early on in the Linux 3.15 kernel cycle are almost all addressed and this next kernel release should happen in the very near future. As some last minute work are some notable fixes for the Intel and Radeon DRM graphics drivers...

http://www.phoronix.com/vr.php?view=MTcwNjA

[Nuc!eoN]

- A Radeon PLL workaround.

Nice! But what is PLL?

[AJenbo]

"Phase-Locked Loop" not that i know what that is :P

[bridgman]

The PLL is essentially a programmable clock generator. It uses a reference clock (something low), a variable-frequency oscillator (used to be voltage controlled, probably still are but not 100% sure), a programmable divider and a phase comparator.

The goal is for the oscillator to be running at a much higher frequency than the reference, so that (oscillator frequency / programmable divider setting) is the same as the reference clock. The phase comparator compares the edges of (reference) and (osc/divider) to see which is running faster, and tweaks the oscillator to run faster or slower as needed, giving you a feedback loop.

A Phase-Locked Loop, you might say.

If you're thinking "OMG that seems fiddly and complicated" the answer would be "yep", especially since the PLL is typically sensitive analog circuitry running on the same die as big noisy digital circuitry. Programming PLLs is one of the few remaining black arts.

[Ericg]

[Something totally on-topic]

Hey, bridgman, can you ask around and see if you can nail down what -exact- versions of mesa / kernel / llvm / etc are needed to get RadeonSI on Kaveri (7850K). 'Cause I'm sitting on Kernel 3.14, Mesa 10.1, and LLVM 3.4... and getting llvmpipe.

Edit: I know its random and off topic, but I got on, saw your post and you are the first AMD Developer / P.O.C. I've seen in days on here.

[rvdboom]

I have a Kaveri 7700K and using kernel 3.14, LLMV 3.4 albeit mesa, glamor, libdrm and xf86-video-ati git pulls. EVerything has been working fine since I bought my system, in january.
Since mesa 10.1 dates from march, I guess what you have should work. I'm would first look for Kaveri kernel firmware or missing glamor, but I guess you probably checked that already.
This was the no-use post of the day.

[bridgman]

Hey, bridgman, can you ask around and see if you can nail down what -exact- versions of mesa / kernel / llvm / etc are needed to get RadeonSI on Kaveri (7850K). 'Cause I'm sitting on Kernel 3.14, Mesa 10.1, and LLVM 3.4... and getting llvmpipe.

I found that pretty much everything I tried worked. That said, I was mucking around with HSA bits so took the lazy route for gfx bits -- Ubuntu 13.10 install plus xorg-edgers or oibaf repo rather than building userspace drivers myself. IIRC the most challenging part of getting a system moved from non-accelerated to accelerated gfx is getting glamor built & set up properly.

Ubuntu 14.04 also "just worked" IIRC, give me a bit and I'll confirm that since I need to update one of my home systems.

[Ericg]

I found that pretty much everything I tried worked. That said, I was mucking around with HSA bits so took the lazy route for gfx bits -- Ubuntu 13.10 install plus xorg-edgers or oibaf repo rather than building userspace drivers myself. IIRC the most challenging part of getting a system moved from non-accelerated to accelerated gfx is getting glamor built & set up properly.

Ubuntu 14.04 also "just worked" IIRC, give me a bit and I'll confirm that since I need to update one of my home systems.

[egriffith@erics-desktop ~]$ dmesg | grep radeon
[    1.643940] [drm] radeon kernel modesetting enabled.
[    1.644419] radeon 0000:00:01.0: VRAM: 2048M 0x0000000000000000 - 0x000000007FFFFFFF (2048M used)
[    1.644421] radeon 0000:00:01.0: GTT: 1024M 0x0000000080000000 - 0x00000000BFFFFFFF
[    1.644505] [drm] radeon: 2048M of VRAM memory ready
[    1.644506] [drm] radeon: 1024M of GTT memory ready.
[    1.644539] cik_cp: Failed to load firmware "radeon/KAVERI_pfp.bin"
[    1.644618] radeon 0000:00:01.0: Fatal error during GPU init
[    1.644655] [drm] radeon: finishing device.
[    1.651899] [drm] radeon: ttm finalized
[    1.652084] radeon: probe of 0000:00:01.0 failed with error -2
[egriffith@erics-desktop ~]$

[egriffith@erics-desktop ~]$ locate KAVERI
/usr/lib/firmware/radeon/KAVERI_ce.bin
/usr/lib/firmware/radeon/KAVERI_me.bin
/usr/lib/firmware/radeon/KAVERI_mec.bin
/usr/lib/firmware/radeon/KAVERI_pfp.bin
/usr/lib/firmware/radeon/KAVERI_rlc.bin
/usr/lib/firmware/radeon/KAVERI_sdma.bin
[egriffith@erics-desktop ~]$

Glamor's installed and at the max version Fedora 20 has available. If you've got thoughts, awesome. If not i'll make an official bug report and let the Fedora guys deal with it.

[asdfblah]

@Ericg: Shouldn't those files be in /lib/firmware/radeon/ ?

[bridgman]

Glamor's installed and at the max version Fedora 20 has available. If you've got thoughts, awesome. If not i'll make an official bug report and let the Fedora guys deal with it.

IIRC there's a problem with F20 installing on Kaveri. I think the workaround was to force nomodeset (radeon.modeset=0) when booting the install media and that was all, will see if I can dig up some notes.

We switched to F21, and that seemed to work pretty well (at least certain daily builds ).