Re: [stable] Regression in 2.6.32.2: radeon KMS hangs system

[Michael T. <mj...@tl...>]

Johannes Hirte wrote:
> With 2.6.32.2 the system hangs completely with black screen when modprobing 
> radeon with modeset=1. I was able to connect via ssh, but after entering the 
> password nothing happend. I didn't got a prompt. Only SysRq worked. I've 
> tracked it down to the following patch:
> 
> From 500b758725314ab1b5316eb0caa5b0fa26740e6b Mon Sep 17 00:00:00 2001
> From: Alex Deucher <ale...@gm...>
> Date: Wed, 2 Dec 2009 11:46:52 -0500
> Subject: drm/radeon/kms: handle vblanks properly with dpms on

Confirmed here on amd780g chipset.  I was about to debug/bisect the issue
right when the email arrived.  Reverting this patch makes my system bootable
again.

/mjt

> From: Alex Deucher <ale...@gm...>
> 
> commit 500b758725314ab1b5316eb0caa5b0fa26740e6b upstream.
> 
> avivo chips
> 
> Copied from pre-avivo code.
> 
> Signed-off-by: Alex Deucher <ale...@gm...>
> Signed-off-by: Dave Airlie <ai...@re...>
> Signed-off-by: Greg Kroah-Hartman <gr...@su...>
...