Re: [drm:init_ring_common] *ERROR* render ring head not reset to zero

From: Chris Wilson
Date: Sun Dec 05 2010 - 16:43:12 EST


On Sun, 5 Dec 2010 06:28:25 +0000 (UTC), Sriram <sri.kmb@xxxxxxxxx> wrote:
> Please explain what this error means & why it is happening...

We wrote a zero into the register (whilst the ring is completely idle,
supposedly anyway) and read back a non-zero value. We believe the silicon
is doing evil things, we workaround it by writing the value again, and
continue on our merry way.

The dance only gets more complex as the hardware evolves.
-Chris

--
Chris Wilson, Intel Open Source Technology Centre
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