[PATCH 2/2] uninorth: Add module param 'aperture' for aperture size

Michel Dänzer michel at tungstengraphics.com
Tue Aug 22 18:55:54 EST 2006

On Tue, 2006-08-22 at 17:25 +1000, Benjamin Herrenschmidt wrote:
> On Mon, 2006-08-21 at 18:09 +0200, Michel Dänzer wrote:
> > In contrast to most if not all PC BIOSes, OpenFirmware (OF) on PowerMacs with
> > UniNorth bridges does not allow changing the aperture size. The size set up by
> > OF is usually 16 MB, which is too low for graphics intensive environments.
> > Hence, add a module parameter that allows changing the aperture size at driver
> > initialization time. When the parameter is not specified, the default is still
> > to leave the size unchanged, usually as set up by OF.
> The right fix is to allow changing it by the driver ... can't we do it
> such that AGPSize will work & change it ? 

Not sure, but it seems like the aperture size is fixed at backend
initialization time, i.e. in the driver's probe hook.

> It's basically expected that we set it ourselves and a module option 
> doesn't seem like a terribly good idea to me...

Well, wasn't it you who suggested this? :)

> Maybe we should just have the driver default to something more sensible
> in addition to what AGPSize comes from userland ? like 64M ?

Might be a good idea.

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

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