[PATCH v3 11/12] drm/i915: Enable the maxfifo PM5 mode when appropriate on CHV

ville.syrjala
2015-03-05T19:20:36Z

From: Ville Syrjälä <ville.syrjala@linux.intel.com>

CHV has a new knob in Punit to select between some memory power savings
modes PM2 and PM5. We can allow the deeper PM5 when maxfifo mode is
enabled, so let's do so in the hopes for moar power savings.

v2: Put the thing into a separate function to avoid churn later
v3: Don't break VLV

Reviewed-by: Vijay Purushothaman <vijay.a.purushothaman@linux.intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
---
drivers/gpu/drm/i915/i915_reg.h | 3 +++
drivers/gpu/drm/i915/intel_pm.c | 18 ++++++++++++++++++
2 files changed, 21 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 145f0d4..5a20f58 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -552,6 +552,9 @@
#define DSPFREQSTAT_MASK (0x3 << DSPFREQSTAT_SHIFT)
#define DSPFREQGUAR_SHIFT 14
#define DSPFREQGUAR_MASK (0x3 << DSPFREQGUAR_SHIFT)
+#define DSP_MAXFIFO_PM5_STATUS (1 << 22) /* chv */
+#define DSP_AUTO_CDCLK_GATE_DISABLE (1 << 7) /* chv */
+#define DSP_MAXFIFO_PM5_ENABLE (1 << 6) /* chv */
#define _DP_SSC(val, pipe) ((val) << (2 * (pipe)))
#define DP_SSC_MASK(pipe) _DP_SSC(0x3, (pipe))
#define DP_SSC_PWR_ON(pipe) _DP_SSC(0x0, (pipe))
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 497847c..1dd82ec 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -235,6 +235,22 @@ static const struct cxsr_latency *intel_get_cxsr_latency(int is_desktop,
return NULL;
}

+static void chv_set_memory_pm5(struct drm_i915_private *dev_priv, bool enable)
+{
+ u32 val;
+
+ mutex_lock(&dev_priv->rps.hw_lock);
+
+ val = vlv_punit_read(dev_priv, PUNIT_REG_DSPFREQ);
+ if (enable)
+ val |= DSP_MAXFIFO_PM5_ENABLE;
+ else
+ val &= ~DSP_MAXFIFO_PM5_ENABLE;
+ vlv_punit_write(dev_priv, PUNIT_REG_DSPFREQ, val);
+
+ mutex_unlock(&dev_priv->rps.hw_lock);
+}
+
void intel_set_memory_cxsr(struct drm_i915_private *dev_priv, bool enable)
{
struct drm_device *dev = dev_priv->dev;
@@ -242,6 +258,8 @@ void intel_set_memory_cxsr(struct drm_i915_private *dev_priv, bool enable)

if (IS_VALLEYVIEW(dev)) {
I915_WRITE(FW_BLC_SELF_VLV, enable ? FW_CSPWRDWNEN : 0);
+ if (IS_CHERRYVIEW(dev))
+ chv_set_memory_pm5(dev_priv, enable);
} else if (IS_G4X(dev) || IS_CRESTLINE(dev)) {
I915_WRITE(FW_BLC_SELF, enable ? FW_BLC_SELF_EN : 0);
} else if (IS_PINEVIEW(dev)) {
--
2.0.5