Initial DRI3000 protocol specs available

[Keith Packard]

Aaron Plattner <aplattner at nvidia.com> writes:

> Why is there a stride here if all it is is an indirect way of 
> calculating a total size?  If the total size is what the server cares 
> about, then it seems like the client should just send that.

I don't need the size, I need the stride. I could just assert that
width/height are sufficient to compute the stride on both sides of the
wire, but we've had image format adventures in the past of this sort and
I'd like to make sure we have sufficient information to reconstruct the
precise layout.

The i915 kernel driver can tell me the tiling format of a GEM buffer,
but it refuses to hand back the stride, so I stuck this into the
protocol as it will be useful for at least that chip.

> Not all tiled formats fit nicely into a height * "stride" = total 
> equation with "stride" being an integer.

Sure, I'd imagine it'd be something like (tiles-wide * tile-width *
tiles-high * tile-height) where tiles-wide and tiles-high are big enough
to cover the specified image size.

I'd obviously prefer to not just pass a pile of driver-specific data in
this request, and 'stride' feels like it's skating close to that
edge.

-- 
keith.packard at intel.com
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