drm/i915: Simplify vlv/chv rc6 residency calculation

We have the czclk frequency in dev_priv now, so let's just use it
when converting the rc6 counters to milliseconds. This eliminates
a bunch of hairy code that essentially tries to extract the czclk
frequency using yet another method.

v2: Fix typos in commit message (Imre)

Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

diff --git a/drivers/gpu/drm/i915/i915_sysfs.c b/drivers/gpu/drm/i915/i915_sysfs.c
index 55bd04c6b9390d1d5cd21a26dea49861cbcff44e..74086eb5bf8351f97f6b645aa5d41818e92aeba1 100644 (file)
--- a/drivers/gpu/drm/i915/i915_sysfs.c
+++ b/drivers/gpu/drm/i915/i915_sysfs.c
@@ -39,7 +39,7 @@ static u32 calc_residency(struct drm_device *dev, const u32 reg)
 {
        struct drm_i915_private *dev_priv = dev->dev_private;
        u64 raw_time; /* 32b value may overflow during fixed point math */
-       u64 units = 128ULL, div = 100000ULL, bias = 100ULL;
+       u64 units = 128ULL, div = 100000ULL;
        u32 ret;
 
        if (!intel_enable_rc6(dev))
@@ -49,41 +49,16 @@ static u32 calc_residency(struct drm_device *dev, const u32 reg)
 
        /* On VLV and CHV, residency time is in CZ units rather than 1.28us */
        if (IS_VALLEYVIEW(dev)) {
-               u32 clk_reg, czcount_30ns;
-
-               if (IS_CHERRYVIEW(dev))
-                       clk_reg = CHV_CLK_CTL1;
-               else
-                       clk_reg = VLV_CLK_CTL2;
-
-               czcount_30ns = I915_READ(clk_reg) >> CLK_CTL2_CZCOUNT_30NS_SHIFT;
-
-               if (!czcount_30ns) {
-                       WARN(!czcount_30ns, "bogus CZ count value");
-                       ret = 0;
-                       goto out;
-               }
-
-               if (IS_CHERRYVIEW(dev) && czcount_30ns == 1) {
-                       /* Special case for 320Mhz */
-                       div = 10000000ULL;
-                       units = 3125ULL;
-               } else {
-                       czcount_30ns += 1;
-                       div = 1000000ULL;
-                       units = DIV_ROUND_UP_ULL(30ULL * bias, czcount_30ns);
-               }
+               units = 1;
+               div = dev_priv->czclk_freq;
 
                if (I915_READ(VLV_COUNTER_CONTROL) & VLV_COUNT_RANGE_HIGH)
                        units <<= 8;
-
-               div = div * bias;
        }
 
        raw_time = I915_READ(reg) * units;
        ret = DIV_ROUND_UP_ULL(raw_time, div);
 
-out:
        intel_runtime_pm_put(dev_priv);
        return ret;
 }