[Intel-gfx] [PATCH] drm/i915/cnl: Get RC6 working.

[Rodrigo Vivi]

On CNL, individual wake rate limit was added to each engine.

GT can only go to RC6 if both Render and Media engines are
individually qualified. So we need to set their individual
wake rate limit.

+-----------------+---------------+--------------+--------------+
|                 |    GT RC6     |  Render C6   |   Media C6   |
+-----------------+---------------+--------------+--------------+
| Wake rate limit | 0xA09C[31:16] | 0xA09C[15:0] | 0xA0A0[15:0] |
+-----------------+---------------+--------------+--------------+

v2: - Tune Render and Media wake rate values according to some extra
      info I got from HW engineers. Value can be tuned, but for now
      these are the recommended values.
    - Fix typos pointed by James.

Cc: Nathan Ciobanu <nathan.d.ciobanu at intel.com>
Cc: Wayne Boyer <wayne.boyer at intel.com>
Cc: Joe Konno <joe.konno at linux.intel.com>
Cc: David Weinehall <david.weinehall at linux.intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi at intel.com>
Reviewed-by: James Ausmus <james.ausmus at intel.com>
---
 drivers/gpu/drm/i915/i915_reg.h |  1 +
 drivers/gpu/drm/i915/intel_pm.c | 15 +++++++++++----
 2 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 68a58cce6ab1..f138eae82bf0 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -7905,6 +7905,7 @@ enum {
 #define GEN6_RC1_WAKE_RATE_LIMIT		_MMIO(0xA098)
 #define GEN6_RC6_WAKE_RATE_LIMIT		_MMIO(0xA09C)
 #define GEN6_RC6pp_WAKE_RATE_LIMIT		_MMIO(0xA0A0)
+#define GEN10_MEDIA_WAKE_RATE_LIMIT		_MMIO(0xA0A0)
 #define GEN6_RC_EVALUATION_INTERVAL		_MMIO(0xA0A8)
 #define GEN6_RC_IDLE_HYSTERSIS			_MMIO(0xA0AC)
 #define GEN6_RC_SLEEP				_MMIO(0xA0B0)
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 5fdae39b1969..742d5455b201 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -6605,12 +6605,19 @@ static void gen9_enable_rc6(struct drm_i915_private *dev_priv)
 	I915_WRITE(GEN6_RC_CONTROL, 0);
 
 	/* 2b: Program RC6 thresholds.*/
-
-	/* WaRsDoubleRc6WrlWithCoarsePowerGating: Doubling WRL only when CPG is enabled */
-	if (IS_SKYLAKE(dev_priv))
+	if (INTEL_GEN(dev_priv) >= 10) {
+		I915_WRITE(GEN6_RC6_WAKE_RATE_LIMIT, 54 << 16 | 85);
+		I915_WRITE(GEN10_MEDIA_WAKE_RATE_LIMIT, 150);
+	} else if (IS_SKYLAKE(dev_priv)) {
+		/*
+		 * WaRsDoubleRc6WrlWithCoarsePowerGating:skl Doubling WRL only
+		 * when CPG is enabled
+		 */
 		I915_WRITE(GEN6_RC6_WAKE_RATE_LIMIT, 108 << 16);
-	else
+	} else {
 		I915_WRITE(GEN6_RC6_WAKE_RATE_LIMIT, 54 << 16);
+	}
+
 	I915_WRITE(GEN6_RC_EVALUATION_INTERVAL, 125000); /* 12500 * 1280ns */
 	I915_WRITE(GEN6_RC_IDLE_HYSTERSIS, 25); /* 25 * 1280ns */
 	for_each_engine(engine, dev_priv, id)
-- 
2.13.5