[Mesa-dev] [PATCH] i965: Use the predicate enable bit for conditional rendering without stalling

[Neil Roberts]

Kenneth Graunke <kenneth at whitecape.org> writes:

> drm-intel-next must have the new software checker turned on, which
> disallows non-whitelisted register writes (along with libva, so it
> can't really be enabled upstream yet).

For what it's worth, I get the EINVAL error even on the stock Fedora 20
kernel on Haswell (and presumably IvyBridge) so I can only assume the
software checker is already upstream, unless I'm misunderstanding
something.

$ uname -r
3.16.7-200.fc20.x86_64
$ modinfo i915 | grep cmd_parser
parm: enable_cmd_parser:Enable command parsing [...]
      (1=enabled [default], 0=disabled) (int)
$ sudo cat /sys/module/i915/parameters/enable_cmd_parser 
1

If I cat 0 to /sys/module/i915/parameters/enable_cmd_parser then I no
longer get the EINVAL error.

- Neil