possible regression Radeon RV280 (R3xx/R4xx ?) card freeze, re-apply old patch ?

[Michel Dänzer]

On Fre, 2013-11-15 at 08:49 +0100, Jochen Rollwagen wrote:
> I think there are two issues here: the first is the missing alignment 
> workaround, since i'll be upgrading to 3.4.69 anyway i'll insert some 
> diagnostic messages in radeon_device.c and see what happens.

Yes, please do that before speculating more about the problem.


> But i'm pretty certain now that this isn't the cause for the lockups.
> They are probably (quite certainly) caused by the dynamic
> binding/unbinding of AGP memory which the Uninorth chipset used in
> 32-bit powermacs obviously doesn't support.

"doesn't support" is too strong; it's working fine on this PowerBook5,8.
But the older the revision of UniNorth, the more quirks.

> All it supports seems to be statically allocating a 256 MB contigouous
> non-cacheable AGP aperture and using that (since the chipset doesn't
> do any address mapping via the GART as indicated in the OpenBSD code).

It does address mapping for the GPU, that's the whole point of the GART.
What UniNorth doesn't do in contrast to most AGP bridges is provide a
linear aperture to the CPU as well. But that shouldn't be an issue per
se.

> So to get AGP mode working again on those machines one would have to
> disable the dynamic memory stuff. Question: Would that require changes
> in the driver only or also in the DRM ?

It's not really possible with radeon KMS.


-- 
Earthling Michel Dänzer            |                  http://www.amd.com
Libre software enthusiast          |                Mesa and X developer