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From 7d34b5177bdda56a7489ac00c0a2a70322eb99ea Mon Sep 17 00:00:00 2001
From: Matt Roper <matthew.d.roper@intel.com>
Date: Fri, 16 Jul 2021 22:14:20 -0700
Subject: drm/i915: Fix application of WaInPlaceDecompressionHang
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Git-commit: f4fa096ad4c288d80a8ac89b5cc4861e68e8c435
Patch-mainline: v5.15-rc1
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225

On SKL we've been applying this workaround on H0+ steppings, which is
actually backwards; H0 is supposed to be the first stepping where the
workaround is no longer needed.  Flip the bounds so that the workaround
applies to all steppings _before_ H0.

On BXT we've been applying this workaround to all steppings, but the
bspec tells us it's only needed until C0.  Pre-C0 GT steppings only
appeared in pre-production hardware, which we no longer support in the
driver, so we can drop the workaround completely for this platform.

On ICL we've been applying this workaround to all steppings, but there
doesn't seem to be any indication that this workaround was ever needed
for this platform (even now-deprecated page 20196 of the bspec doesn't
mention it).  We can go ahead and drop it.

I also don't see any mention of this workaround being needed for KBL,
although this may be an oversight since the workaround is needed for all
steppings of CFL.  I'll leave the workaround in place for KBL to be
safe.

Bspec: 14091, 33450
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: José Roberto de Souza <jose.souza@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210717051426.4120328-2-matthew.d.roper@intel.com
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/gpu/drm/i915/gt/intel_workarounds.c | 20 ++------------------
 1 file changed, 2 insertions(+), 18 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_workarounds.c b/drivers/gpu/drm/i915/gt/intel_workarounds.c
index 7731db33c46a..76a3b5d5e9dc 100644
--- a/drivers/gpu/drm/i915/gt/intel_workarounds.c
+++ b/drivers/gpu/drm/i915/gt/intel_workarounds.c
@@ -838,23 +838,12 @@ skl_gt_workarounds_init(struct drm_i915_private *i915, struct i915_wa_list *wal)
 		    GEN8_EU_GAUNIT_CLOCK_GATE_DISABLE);
 
 	/* WaInPlaceDecompressionHang:skl */
-	if (IS_SKL_GT_STEP(i915, STEP_H0, STEP_FOREVER))
+	if (IS_SKL_GT_STEP(i915, STEP_A0, STEP_H0 - 1))
 		wa_write_or(wal,
 			    GEN9_GAMT_ECO_REG_RW_IA,
 			    GAMT_ECO_ENABLE_IN_PLACE_DECOMPRESS);
 }
 
-static void
-bxt_gt_workarounds_init(struct drm_i915_private *i915, struct i915_wa_list *wal)
-{
-	gen9_gt_workarounds_init(i915, wal);
-
-	/* WaInPlaceDecompressionHang:bxt */
-	wa_write_or(wal,
-		    GEN9_GAMT_ECO_REG_RW_IA,
-		    GAMT_ECO_ENABLE_IN_PLACE_DECOMPRESS);
-}
-
 static void
 kbl_gt_workarounds_init(struct drm_i915_private *i915, struct i915_wa_list *wal)
 {
@@ -942,11 +931,6 @@ icl_gt_workarounds_init(struct drm_i915_private *i915, struct i915_wa_list *wal)
 {
 	icl_wa_init_mcr(i915, wal);
 
-	/* WaInPlaceDecompressionHang:icl */
-	wa_write_or(wal,
-		    GEN9_GAMT_ECO_REG_RW_IA,
-		    GAMT_ECO_ENABLE_IN_PLACE_DECOMPRESS);
-
 	/* WaModifyGamTlbPartitioning:icl */
 	wa_write_clr_set(wal,
 			 GEN11_GACB_PERF_CTRL,
@@ -1081,7 +1065,7 @@ gt_init_workarounds(struct drm_i915_private *i915, struct i915_wa_list *wal)
 	else if (IS_KABYLAKE(i915))
 		kbl_gt_workarounds_init(i915, wal);
 	else if (IS_BROXTON(i915))
-		bxt_gt_workarounds_init(i915, wal);
+		gen9_gt_workarounds_init(i915, wal);
 	else if (IS_SKYLAKE(i915))
 		skl_gt_workarounds_init(i915, wal);
 	else if (IS_HASWELL(i915))
-- 
2.38.1