[Mesa-dev] [PATCH] i965/hsw: compute DDX in a subspan based only on top row

[Kenneth Graunke]

On 09/20/2013 08:30 AM, Ian Romanick wrote:
> On 09/20/2013 09:50 AM, Paul Berry wrote:
[snip]
>> Since the SAMPLER_MODE setting allows us to trade off quality vs
>> performance, we're also interested to know whether a value less than
>> 0x1f is sufficient to produce the performance improvement in Xonotic--it
>> would be nice if we could find a "sweet spot" for this setting that
>> produces the performance improvement we need without sacrificing too
>> much quality.
> 
> How about if we just give a driconf option to adjust it.  Then gamers
> can make their own choice.  For applications where it know it makes a
> big difference, we can provide a default non-0 value in the system driconf.

Because you can't (yet) program registers from userspace unless you're root.

I would like to use the same default value as Windows.  I'm fine with
making it tunable beyond that.

--Ken