On Wed, Mar 15, 2017 at 05:43:01PM +0200, Mika Kuoppala wrote: > Vlv and chv residency counters are 40 bits in width. > With a control bit, we can choose between upper or lower > 32 bit window into this counter. > > Lets toggle this bit on and off on and read both parts. > As a result we can push the wrap from 13 seconds to 54 > minutes. > > v2: commit msg, loop readability, goto elimination (Chris) > > Reported-by: Len Brown <len.br...@intel.com>
References: https://bugs.freedesktop.org/show_bug.cgi?id=94852 > Cc: Chris Wilson <ch...@chris-wilson.co.uk> > Cc: Ville Syrjälä <ville.syrj...@linux.intel.com> > Signed-off-by: Mika Kuoppala <mika.kuopp...@intel.com> > --- > u64 intel_rc6_residency_us(struct drm_i915_private *dev_priv, > const i915_reg_t reg) > { > - u64 raw_time; /* 32b value may overflow during fixed point math */ > - u64 units = 128000ULL, div = 100000ULL; > - u64 ret; > + u64 time_hw, units, div, residency_us; > > if (!intel_enable_rc6()) > return 0; > @@ -8367,16 +8406,21 @@ u64 intel_rc6_residency_us(struct drm_i915_private > *dev_priv, > units = 1000; > div = dev_priv->czclk_freq; > > - if (I915_READ(VLV_COUNTER_CONTROL) & VLV_COUNT_RANGE_HIGH) > - units <<= 8; > + time_hw = vlv_residency_raw(dev_priv, reg); > } else if (IS_GEN9_LP(dev_priv)) { > units = 1000; > div = 1200; /* 833.33ns */ > + > + time_hw = I915_READ(reg); > + } else { > + units = 128000; /* 1.28us */ > + div = 100000; > + > + time_hw = I915_READ(reg); > } > > - raw_time = I915_READ(reg) * units; > - ret = DIV_ROUND_UP_ULL(raw_time, div); > + residency_us = DIV_ROUND_UP_ULL(time_hw * units, div); This calc doesn't need to be inside the rpm, so just > > intel_runtime_pm_put(dev_priv); > - return ret; > + return residency_us; return DIV_ROUND_UP_ULL(time_hw * units, div); Either way, Reviewed-by: Chris Wilson <ch...@chris-wilson.co.uk> -Chris -- Chris Wilson, Intel Open Source Technology Centre _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx
