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* [Intel-gfx] [PATCH] drm/i915/tgl: Add Wa_1608008084
@ 2020-02-22  0:28 Lucas De Marchi
  2020-02-22  0:36 ` Souza, Jose
                   ` (2 more replies)
  0 siblings, 3 replies; 8+ messages in thread
From: Lucas De Marchi @ 2020-02-22  0:28 UTC (permalink / raw)
  To: intel-gfx; +Cc: Lucas De Marchi

Wa_1608008084 is an additional WA that applies to writes on FF_MODE2
register. We can't read it back either from CPU or GPU. Since the other
bits should be 0, recommendation to handle Wa_1604555607 is to actually
just write the timer value.

Do a write only and don't try to read it, neither before or after
the WA is applied.

Fixes: ff690b2111ba ("drm/i915/tgl: Implement Wa_1604555607")
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
---
 drivers/gpu/drm/i915/gt/intel_workarounds.c | 22 ++++++++++-----------
 1 file changed, 10 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_workarounds.c b/drivers/gpu/drm/i915/gt/intel_workarounds.c
index 887e0dc701f7..0d76e1d6ec87 100644
--- a/drivers/gpu/drm/i915/gt/intel_workarounds.c
+++ b/drivers/gpu/drm/i915/gt/intel_workarounds.c
@@ -580,24 +580,22 @@ static void icl_ctx_workarounds_init(struct intel_engine_cs *engine,
 static void tgl_ctx_workarounds_init(struct intel_engine_cs *engine,
 				     struct i915_wa_list *wal)
 {
-	u32 val;
-
 	/* Wa_1409142259:tgl */
 	WA_SET_BIT_MASKED(GEN11_COMMON_SLICE_CHICKEN3,
 			  GEN12_DISABLE_CPS_AWARE_COLOR_PIPE);
 
-	/* Wa_1604555607:tgl */
-	val = intel_uncore_read(engine->uncore, FF_MODE2);
-	val &= ~FF_MODE2_TDS_TIMER_MASK;
-	val |= FF_MODE2_TDS_TIMER_128;
 	/*
-	 * FIXME: FF_MODE2 register is not readable till TGL B0. We can
-	 * enable verification of WA from the later steppings, which enables
-	 * the read of FF_MODE2.
+	 * Wa_1604555607:gen12
+	 * FF_MODE2 register is not readable till TGL B0, either by CPU or GPU.
+	 *
+	 * Wa_1608008084:gen12
+	 * FF_MODE2 register will return the wrong value when read. The default
+	 * value for this register is zero for all fields and there are no bit
+	 * masks. So instead of doing a RMW we should just write the TDS timer
+	 * value for Wa_1604555607.
 	 */
-	wa_add(wal, FF_MODE2, FF_MODE2_TDS_TIMER_MASK, val,
-	       IS_TGL_REVID(engine->i915, TGL_REVID_A0, TGL_REVID_A0) ? 0 :
-			    FF_MODE2_TDS_TIMER_MASK);
+	wa_add(wal, FF_MODE2, FF_MODE2_TDS_TIMER_MASK,
+	       FF_MODE2_TDS_TIMER_128, 0);
 }
 
 static void
-- 
2.24.0

_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx

^ permalink raw reply related	[flat|nested] 8+ messages in thread
* [Intel-gfx] [PATCH] drm/i915/tgl: Add Wa_1608008084
@ 2020-02-24 19:12 Lucas De Marchi
  0 siblings, 0 replies; 8+ messages in thread
From: Lucas De Marchi @ 2020-02-24 19:12 UTC (permalink / raw)
  To: intel-gfx; +Cc: Lucas De Marchi, ramlingam.c

Wa_1608008084 is an additional WA that applies to writes on FF_MODE2
register. We can't read it back either from CPU or GPU. Since the other
bits should be 0, recommendation to handle Wa_1604555607 is to actually
just write the timer value.

Do a write only and don't try to read it, neither before or after
the WA is applied.

Fixes: ff690b2111ba ("drm/i915/tgl: Implement Wa_1604555607")
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: José Roberto de Souza <jose.souza@intel.com>
---
 drivers/gpu/drm/i915/gt/intel_workarounds.c | 19 +++++++------------
 1 file changed, 7 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_workarounds.c b/drivers/gpu/drm/i915/gt/intel_workarounds.c
index 887e0dc701f7..06cef3c18f26 100644
--- a/drivers/gpu/drm/i915/gt/intel_workarounds.c
+++ b/drivers/gpu/drm/i915/gt/intel_workarounds.c
@@ -580,24 +580,19 @@ static void icl_ctx_workarounds_init(struct intel_engine_cs *engine,
 static void tgl_ctx_workarounds_init(struct intel_engine_cs *engine,
 				     struct i915_wa_list *wal)
 {
-	u32 val;
-
 	/* Wa_1409142259:tgl */
 	WA_SET_BIT_MASKED(GEN11_COMMON_SLICE_CHICKEN3,
 			  GEN12_DISABLE_CPS_AWARE_COLOR_PIPE);
 
-	/* Wa_1604555607:tgl */
-	val = intel_uncore_read(engine->uncore, FF_MODE2);
-	val &= ~FF_MODE2_TDS_TIMER_MASK;
-	val |= FF_MODE2_TDS_TIMER_128;
 	/*
-	 * FIXME: FF_MODE2 register is not readable till TGL B0. We can
-	 * enable verification of WA from the later steppings, which enables
-	 * the read of FF_MODE2.
+	 * Wa_1604555607:gen12 and Wa_1608008084:gen12
+	 * FF_MODE2 register will return the wrong value when read. The default
+	 * value for this register is zero for all fields and there are no bit
+	 * masks. So instead of doing a RMW we should just write the TDS timer
+	 * value for Wa_1604555607.
 	 */
-	wa_add(wal, FF_MODE2, FF_MODE2_TDS_TIMER_MASK, val,
-	       IS_TGL_REVID(engine->i915, TGL_REVID_A0, TGL_REVID_A0) ? 0 :
-			    FF_MODE2_TDS_TIMER_MASK);
+	wa_add(wal, FF_MODE2, FF_MODE2_TDS_TIMER_MASK,
+	       FF_MODE2_TDS_TIMER_128, 0);
 }
 
 static void
-- 
2.24.0

_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx

^ permalink raw reply related	[flat|nested] 8+ messages in thread
end of thread, other threads:[~2020-02-24 21:54 UTC | newest]

Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-02-22  0:28 [Intel-gfx] [PATCH] drm/i915/tgl: Add Wa_1608008084 Lucas De Marchi
2020-02-22  0:36 ` Souza, Jose
2020-02-22  1:39   ` Lucas De Marchi
2020-02-24 21:10   ` Chris Wilson
2020-02-24 21:54     ` Lucas De Marchi
2020-02-22  4:30 ` [Intel-gfx] ✓ Fi.CI.BAT: success for " Patchwork
2020-02-24 16:58 ` [Intel-gfx] ✓ Fi.CI.IGT: " Patchwork
2020-02-24 19:12 [Intel-gfx] [PATCH] " Lucas De Marchi

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