[Intel-gfx] [PATCH] lib/rendercopy_gen9: Setup Push constant pointer before sending BTP commands

[Ben Widawsky]

On Wed, Aug 12, 2015 at 03:10:18PM +0300, Joonas Lahtinen wrote:
> On ke, 2015-08-12 at 12:26 +0100, Arun Siluvery wrote:
> > From Gen9, by default push constant command is not committed to the 
> > shader unit
> > untill the corresponding shader's BTP_* command is parsed. This is 
> > the
> > behaviour when set shader is enabled. This patch updates the batch to 
> > follow
> > this requirement otherwise it results in gpu hang.
> > 
> > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=89959
> > 
> > Set shader need to be disabled if legacy behaviour is required.
> > 
> > Cc: Ben Widawsky <benjamin.widawsky at intel.com>
> > Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
> > Cc: Mika Kuoppala <mika.kuoppala at intel.com>
> > Signed-off-by: Arun Siluvery <arun.siluvery at linux.intel.com>
> 
> Reviewed-by: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
> 

Repeating what I said on the mesa thread:
Does anyone understand why this actually causes a hang on the IGT test? I
certainly don't. The docs are pretty clear that the constant command is not
committed until the BTP command, but I can't make any sense of how it related to
a GPU hang.

[snip]

---
Ben Widawsky, Intel Open Source Technology Center