Mesa (master): i965/gen8+: Invalidate color calc state when switching to the GPGPU pipeline.

[Francisco Jerez]

Module: Mesa
Branch: master
Commit: 044acb9256046bebec890cac7e42043754459fc2
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=044acb9256046bebec890cac7e42043754459fc2

Author: Francisco Jerez <currojerez at riseup.net>
Date:   Sat Jan  2 18:35:28 2016 -0800

i965/gen8+: Invalidate color calc state when switching to the GPGPU pipeline.

This hardware bug can cause a hang on context restore while the
current pipeline is set to GPGPU (BDWGFX HSD 1909593).  In addition to
clearing the valid bit, mark the CC state as dirty to make sure that
the CC indirect state pointer is re-emitted when we switch back to the
3D pipeline.

Reviewed-by: Matt Turner <mattst88 at gmail.com>
Reviewed-by: Kenneth Graunke <kenneth at whitecape.org>

---

 src/mesa/drivers/dri/i965/brw_misc_state.c |   20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/src/mesa/drivers/dri/i965/brw_misc_state.c b/src/mesa/drivers/dri/i965/brw_misc_state.c
index cf6ba5b..2b2f031 100644
--- a/src/mesa/drivers/dri/i965/brw_misc_state.c
+++ b/src/mesa/drivers/dri/i965/brw_misc_state.c
@@ -868,6 +868,26 @@ brw_emit_select_pipeline(struct brw_context *brw, enum brw_pipeline pipeline)
    const uint32_t _3DSTATE_PIPELINE_SELECT =
       is_965 ? CMD_PIPELINE_SELECT_965 : CMD_PIPELINE_SELECT_GM45;
 
+   if (brw->gen >= 8 && brw->gen < 10) {
+      /* From the Broadwell PRM, Volume 2a: Instructions, PIPELINE_SELECT:
+       *
+       *   Software must clear the COLOR_CALC_STATE Valid field in
+       *   3DSTATE_CC_STATE_POINTERS command prior to send a PIPELINE_SELECT
+       *   with Pipeline Select set to GPGPU.
+       *
+       * The internal hardware docs recommend the same workaround for Gen9
+       * hardware too.
+       */
+      if (pipeline == BRW_COMPUTE_PIPELINE) {
+         BEGIN_BATCH(2);
+         OUT_BATCH(_3DSTATE_CC_STATE_POINTERS << 16 | (2 - 2));
+         OUT_BATCH(0);
+         ADVANCE_BATCH();
+
+         brw->ctx.NewDriverState |= BRW_NEW_CC_STATE;
+      }
+   }
+
    /* Select the pipeline */
    BEGIN_BATCH(1);
    OUT_BATCH(_3DSTATE_PIPELINE_SELECT << 16 |