[PATCH] drm/radeon/kms: R3XX-R4XX fix GPU reset code

[Michel Dänzer]

On Mon, 2010-04-26 at 22:23 +0200, Jerome Glisse wrote: 
> Previous reset code leaded to computer hard lockup (need to unplug
> the power too reboot the computer) on various configuration. This
> patch change the reset code to avoid hard lockup. The GPU reset
> is failing most of the time but at least user can log in remotely
> or properly shutdown the computer.
> 
> Two issues were leading to hard lockup :
> - Writting to the scratch register lead to hard lockup most likely
> because the write back mecanism is in fuzy state after GPU lockup.
> - Resetting the GPU memory controller and not reinitializing it
> after leaded to hard lockup. We did only reinitialize in case of
> successfull reset thus unsuccessfull reset quickly leaded to hard
> lockup.
> 
> Signed-off-by: Jerome Glisse <jglisse at redhat.com>

Unfortunately, this doesn't seem to help for the RV350 in my PowerBook.
GPU lockups still turn into machine hardlocks, which is a regression
from before the GPU reset rework.


-- 
Earthling Michel Dänzer           |                http://www.vmware.com
Libre software enthusiast         |          Debian, X and DRI developer