[Dri-devel] AGP writeback experiments

[Felix <fx...@gm...>]

Benjamin,

I played around with some AGP bits as you suggested in yesterday's IRC
meeting. I found out that writeback works with 1x and 2x AGP but not
with 4x.

The other things I tried didn't have any effect with 4x AGP:
 - disable fast writes
 - set rq depth to 1
 - enabling SBA

I'm not sure about SBA, though. If I'm not mistaken you wrote that SDA
is controlled by bit 9 in mode. Bit 9 is set by default. If I clear it
the xserver locks up. So I assume bit 9 is AGP-enable and bit 8 is SBA.
Enabling bit 8 doesn't help.

------------    __\|/__    ___     ___       -------------------------
 Felix       ___\_e -_/___/ __\___/ __\_____   You can do anything,
   Kühling  (_____\Ä/____/ /_____/ /________)  just not everything
 fx...@gm...       \___/   \___/   U        at the same time.