[Intel-gfx] [PATCH] drm/i915: Restore GT coarse power gating workaround

[Imre Deak]

The workaround to disable coarse power gating is still needed on SKL
GT3/GT4 machines and since the RC6 context corruption was discovered by
the hardware team also on all GEN9 machines. Restore applying the
workaround.

Fixes: c113236718e8 ("drm/i915: Extract GT render sleep (rc6) management")
Testcase: igt/intel_gt_pm_late_selftests/live_rc6_ctx
Cc: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Andi Shyti <andi.shyti at intel.com>
Signed-off-by: Imre Deak <imre.deak at intel.com>
---
 drivers/gpu/drm/i915/gt/intel_rc6.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_rc6.c b/drivers/gpu/drm/i915/gt/intel_rc6.c
index f7c0baeb3793..de2d302e8d55 100644
--- a/drivers/gpu/drm/i915/gt/intel_rc6.c
+++ b/drivers/gpu/drm/i915/gt/intel_rc6.c
@@ -175,8 +175,10 @@ static void gen9_rc6_enable(struct intel_rc6 *rc6)
 	    GEN6_RC_CTL_RC6_ENABLE |
 	    rc6_mode);
 
-	set(uncore, GEN9_PG_ENABLE,
-	    GEN9_RENDER_PG_ENABLE | GEN9_MEDIA_PG_ENABLE);
+	/* WaRsDisableCoarsePowerGating:skl,cnl - Render/Media PG need to be disabled with RC6. */
+	if (!NEEDS_WaRsDisableCoarsePowerGating(rc6_to_i915(rc6)))
+		set(uncore, GEN9_PG_ENABLE,
+		    GEN9_RENDER_PG_ENABLE | GEN9_MEDIA_PG_ENABLE);
 }
 
 static void gen8_rc6_enable(struct intel_rc6 *rc6)
-- 
2.17.1