On Tue, Nov 18, 2014 at 02:38:25PM +0530, Deepak S wrote: > > On Tuesday 11 November 2014 02:25 AM, ville.syrjala@xxxxxxxxxxxxxxx wrote: > > From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > > > > Currently we miscalculate the GPU frequency on chv. This causes us to > > report the GPU frequency as half of what it really is. Drop the extra > > factor of 2 from the calculations to get the correct answer. > > > > Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > > --- > > drivers/gpu/drm/i915/intel_pm.c | 4 ++-- > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c > > index 03fbb45..74e4293 100644 > > --- a/drivers/gpu/drm/i915/intel_pm.c > > +++ b/drivers/gpu/drm/i915/intel_pm.c > > @@ -7329,7 +7329,7 @@ static int chv_gpu_freq(struct drm_i915_private *dev_priv, int val) > > if (div < 0) > > return div; > > > > - return DIV_ROUND_CLOSEST(czclk_freq * val, 2 * div) / 2; > > + return DIV_ROUND_CLOSEST(czclk_freq * val, 2 * div); > > I think CHV is 2 X cck, shouldn't we report the cck freq and not 2 *cck? Hmm. Once again the docs are extremely unclear. Dropping the 2x factor gives me the same numbers that the tables in the docs have. But then the spreadsheet calls it a "2x clock" in some places, which does suggest it might get further divided down by 2. Oh, now I did find a somewhat clear note in the clock HAS: "The dedicated GPLL (Graphics PLL) sends a 2GHz gfx clock to GenLC, which gets divided inside the GenLC block to derive a 1GHz Gfx fast clock." So based on that the original code does make more sense. > > > } > > > > static int chv_freq_opcode(struct drm_i915_private *dev_priv, int val) > > @@ -7341,7 +7341,7 @@ static int chv_freq_opcode(struct drm_i915_private *dev_priv, int val) > > return mul; > > > > /* CHV needs even values */ > > - return DIV_ROUND_CLOSEST(val * 2 * mul, czclk_freq) * 2; > > + return DIV_ROUND_CLOSEST(val * mul, czclk_freq) * 2; > > } > > > > int vlv_gpu_freq(struct drm_i915_private *dev_priv, int val) > > _______________________________________________ > Intel-gfx mailing list > Intel-gfx@xxxxxxxxxxxxxxxxxxxxx > http://lists.freedesktop.org/mailman/listinfo/intel-gfx -- Ville Syrjälä Intel OTC _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
