drm/i915: Use a mask when applying WaProgramL3SqcReg1Default

Otherwise we are blasting other bits in GEN8_L3SQCREG1 that might be important
(although we probably aren't at the moment because 0 seems to be the default
for all the other bits).

v2: Extra parentheses (Michel)

Fixes: 050fc46 ("drm/i915:bxt: implement WaProgramL3SqcReg1DefaultForPerf")
Fixes: 450174f ("drm/i915/chv: Tune L3 SQC credits based on actual latencies")
Signed-off-by: Oscar Mateo <oscar.mateo@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Reviewed-by: Michel Thierry <michel.thierry@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1508271945-14961-1-git-send-email-oscar.mateo@intel.com
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
(cherry picked from commit 930a784d02339be437fec07b3bb7213bde0ed53b)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index ed7cd9e..c9bcc6c 100644 (file)
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -6998,6 +6998,7 @@ enum {
  */
 #define  L3_GENERAL_PRIO_CREDITS(x)            (((x) >> 1) << 19)
 #define  L3_HIGH_PRIO_CREDITS(x)               (((x) >> 1) << 14)
+#define  L3_PRIO_CREDITS_MASK                  ((0x1f << 19) | (0x1f << 14))
 
 #define GEN7_L3CNTLREG1                                _MMIO(0xB01C)
 #define  GEN7_WA_FOR_GEN7_L3_CONTROL                   0x3C47FF8C

diff --git a/drivers/gpu/drm/i915/intel_engine_cs.c b/drivers/gpu/drm/i915/intel_engine_cs.c
index 9ab5969..3c2d9cf 100644 (file)
--- a/drivers/gpu/drm/i915/intel_engine_cs.c
+++ b/drivers/gpu/drm/i915/intel_engine_cs.c
@@ -1048,9 +1048,12 @@ static int bxt_init_workarounds(struct intel_engine_cs *engine)
        }
 
        /* WaProgramL3SqcReg1DefaultForPerf:bxt */
-       if (IS_BXT_REVID(dev_priv, BXT_REVID_B0, REVID_FOREVER))
-               I915_WRITE(GEN8_L3SQCREG1, L3_GENERAL_PRIO_CREDITS(62) |
-                                          L3_HIGH_PRIO_CREDITS(2));
+       if (IS_BXT_REVID(dev_priv, BXT_REVID_B0, REVID_FOREVER)) {
+               u32 val = I915_READ(GEN8_L3SQCREG1);
+               val &= ~L3_PRIO_CREDITS_MASK;
+               val |= L3_GENERAL_PRIO_CREDITS(62) | L3_HIGH_PRIO_CREDITS(2);
+               I915_WRITE(GEN8_L3SQCREG1, val);
+       }
 
        /* WaToEnableHwFixForPushConstHWBug:bxt */
        if (IS_BXT_REVID(dev_priv, BXT_REVID_C0, REVID_FOREVER))

diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index ed66293..0a09f8f 100644 (file)
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -8245,14 +8245,17 @@ static void gen8_set_l3sqc_credits(struct drm_i915_private *dev_priv,
                                   int high_prio_credits)
 {
        u32 misccpctl;
+       u32 val;
 
        /* WaTempDisableDOPClkGating:bdw */
        misccpctl = I915_READ(GEN7_MISCCPCTL);
        I915_WRITE(GEN7_MISCCPCTL, misccpctl & ~GEN7_DOP_CLOCK_GATE_ENABLE);
 
-       I915_WRITE(GEN8_L3SQCREG1,
-                  L3_GENERAL_PRIO_CREDITS(general_prio_credits) |
-                  L3_HIGH_PRIO_CREDITS(high_prio_credits));
+       val = I915_READ(GEN8_L3SQCREG1);
+       val &= ~L3_PRIO_CREDITS_MASK;
+       val |= L3_GENERAL_PRIO_CREDITS(general_prio_credits);
+       val |= L3_HIGH_PRIO_CREDITS(high_prio_credits);
+       I915_WRITE(GEN8_L3SQCREG1, val);
 
        /*
         * Wait at least 100 clocks before re-enabling clock gating.