[PATCH xserver] configure.ac: unconditionally enable kdrive

[Adam Jackson]

On Wed, 2017-11-01 at 21:50 -0700, Matt Turner wrote:
> On Tue, Oct 24, 2017 at 10:27 AM, Matt Turner <mattst88 at gmail.com>
> wrote:
> > Reviewed-by: Matt Turner <mattst88 at gmail.com>
> 
> Please merge. :)

Full disclosure: the reason I haven't is because it exposed that my
test setup was failing to build Xephyr (for exactly the reason the
patch fixes), and that glamor was now failing xts. I am quite sure it
worked in 1.19 at the time, but building 1.19 [1] now was also failing
xts, which points the finger at llvmpipe since it rules out any change
in glamor as the culprit.

I'd already worked around one such regression with llvmpipe [2] but
this one has eluded me. Eric Anholt had written a script to run the
test on a hardware-backed Xephyr, but didn't think we could integrate
it with make check.

I'd like to start doing that, though. In this order:

1) Add the script
2) Add it to make check, guarded by [ -z "$DISPLAY" ]
3) Apply this kdrive patch (assuming it passes on my hardware!)

I think that preserves the greatest amount of bisectable history
without introducing any known-broken tree states. It also means we'd be
testing something more like what people actually run; the set of people
using glamor backed by llvmpipe I suspect is zero, it's uniformly
slower than fb.

Sound reasonable?

[1] - bit of a lie, I had to rewrite the branch history to cluster all
the glamor changes at the end:

https://cgit.freedesktop.org/~ajax/xserver/log/?h=glamor-did-not-regress

[2] - https://lists.freedesktop.org/archives/mesa-dev/2017-February/145536.html

- ajax