KMS causing boot failure

sahrxaa · n00b Joined: 19 Nov 2012 Posts: 7 Location: Cyberspace

Enabling kernel mode setting, as per the instructions for xf86-video-ati, causes my system to hang at boot before anything can be processed, making debugging rather difficult for obvious reasons.

Booting with parameter "nomodeset" allows me to boot but of course X crashes for lack of KMS support.

Rolling back to xf86-video-ati-6.14.4-r1, xorg-server-1.12.4 and xorg-drivers-1.12 with nomodeset active allows me to boot up and startx, but I am confronted with LIBGL errors when starting certain programs.

If I compile relevant KMS options as modules instead of built-in, I can boot but enabling (modprobe radeon modeset=1) causes my screen to loose connection and I am forced to blindly shutdown the system.

It's also worth noting that I have tried several Live CDs from other distributions which enable KMS by default and had the _same_ issue -- failure to boot the livecd without passing "nomodeset" to the kernel.

I will supply any information I can as requested -- I am reasonably linux savvy, but somewhat new to Gentoo and this sort of low-level breakage is way over my head to debug, and I have found absolutely no case examples online similar to this.

Am typing this up from my desktop, since the laptop having these issues is stuck in console with horribly large font making forum posting difficult. I'll dump any requested information onto a USB and post it from my desktop upon request.
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DaggyStyle · Watchman Joined: 22 Mar 2006 Posts: 5945

it is hard to start help you without knowing what gpu you are using.
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sahrxaa · n00b Joined: 19 Nov 2012 Posts: 7 Location: Cyberspace

Voltago · Posted: Sun Dec 02, 2012 10:52 am Post subject:

Have you made sure there is no firmware blob you have to include into your kernel for KMS to work?
(Device Drivers->Generic Driver Options->External firmware blobs to build into the kernel binary, CONFIG_EXTRA_FIRMWARE)

EDIT: Oh yes, I was assuming you are using xf86-video-ati.

DaggyStyle · Watchman Joined: 22 Mar 2006 Posts: 5945

sahrxaa · n00b Joined: 19 Nov 2012 Posts: 7 Location: Cyberspace

DaggyStyle · Watchman Joined: 22 Mar 2006 Posts: 5945

NeddySeagoon · Posted: Sun Dec 02, 2012 1:44 pm Post subject:

sahrxaa,

Have you installed linux-firmware?
Thats more firmware than you could ever need but all the radeon files are there.

Providing you make radeon and radeon KMS support as <M> in the kernel it should just work.
Make it built in is possible but harder as the firmware must be built into the kernel too.
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VoidMage · Watchman Joined: 14 Oct 2006 Posts: 6196

I kinda doubt linux-firmware is required here, but we should probably go back to the basic question - pastebin your kernel config.

Hu · Administrator Joined: 06 Mar 2007 Posts: 23407

Based on the description, it sounds like the monitor is switching to powersave mode. This can happen if the system is (1) using Radeon KMS, (2) not running X, and (3) not configured with the framebuffer console.

OP: in addition to posting the other items requested, please check whether blindly starting X makes the system usable when Radeon KMS is enabled.

sahrxaa · n00b Joined: 19 Nov 2012 Posts: 7 Location: Cyberspace

Upon quite a bit more web crawling, it looks like this is a known, if obscure issue with certain video cards. Older Radeon Mobility cards in particular seem to suffer. The only way afflicted cards can boot is with "nomodeset" parameter or rolling back to earlier packages where KMS isn't mandatory.

This behavior is consistent with every new distro release I've tried, presumably where the latest open source ATI driver is in use. So I suppose this is in the wrong section, though I thought it to be a kernel related problem at first.

I'll file a bug report with the proper folks. _Maybe_ it will be fixed in a later release. Thanks again for the responses.

For posterity, in case someone else is using an Radeon Mobility X2300 and has KMS woes, rolling back to xorg-server-1.12.4, xorg-drivers-1.12 and xf86-video-ati-6.14.4-r1 is a valid workaround. The console is hideous and opengl games are flakey, but everything else works. =/
_________________
The body is a cage, entwining and burdening the mind so as to halt expansion.