| Message ID | 1383684151-595-2-git-send-email-ville.syrjala@linux.intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, 5 Nov 2013 22:42:28 +0200 ville.syrjala@linux.intel.com wrote: > From: Ville Syrjälä <ville.syrjala@linux.intel.com> > > We're currently miscalculating the VLV graphics clock a little bit. > This is caused by rounding the step to integer MHz, which does not > match reality. Change the formula to match the GUnit HAS to give > more accurate answers. > > Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com> > --- > drivers/gpu/drm/i915/intel_pm.c | 35 ++++++++++++----------------------- > 1 file changed, 12 insertions(+), 23 deletions(-) > > diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c > index a5778e5..865035b 100644 > --- a/drivers/gpu/drm/i915/intel_pm.c > +++ b/drivers/gpu/drm/i915/intel_pm.c > @@ -5947,57 +5947,46 @@ int sandybridge_pcode_write(struct drm_i915_private *dev_priv, u8 mbox, u32 val) > > int vlv_gpu_freq(int ddr_freq, int val) > { > - int mult, base; > + int div; > > + /* 4 x czclk */ > switch (ddr_freq) { > case 800: > - mult = 20; > - base = 120; > + div = 10; > break; > case 1066: > - mult = 22; > - base = 133; > + div = 12; > break; > case 1333: > - mult = 21; > - base = 125; > + div = 16; > break; > default: > return -1; > } > > - return ((val - 0xbd) * mult) + base; > + return DIV_ROUND_CLOSEST(ddr_freq * (val + 6 - 0xbd), 4 * div); > } > > int vlv_freq_opcode(int ddr_freq, int val) > { > - int mult, base; > + int mul; > > + /* 4 x czclk */ > switch (ddr_freq) { > case 800: > - mult = 20; > - base = 120; > + mul = 10; > break; > case 1066: > - mult = 22; > - base = 133; > + mul = 12; > break; > case 1333: > - mult = 21; > - base = 125; > + mul = 16; > break; > default: > return -1; > } > > - val /= mult; > - val -= base / mult; > - val += 0xbd; > - > - if (val > 0xea) > - val = 0xea; > - > - return val; > + return DIV_ROUND_CLOSEST(4 * mul * val, ddr_freq) + 0xbd - 6; > } > > void intel_pm_init(struct drm_device *dev) Yeah these values look better at 1066 and 1333. No differences at 800 though. Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c index a5778e5..865035b 100644 --- a/drivers/gpu/drm/i915/intel_pm.c +++ b/drivers/gpu/drm/i915/intel_pm.c @@ -5947,57 +5947,46 @@ int sandybridge_pcode_write(struct drm_i915_private *dev_priv, u8 mbox, u32 val) int vlv_gpu_freq(int ddr_freq, int val) { - int mult, base; + int div; + /* 4 x czclk */ switch (ddr_freq) { case 800: - mult = 20; - base = 120; + div = 10; break; case 1066: - mult = 22; - base = 133; + div = 12; break; case 1333: - mult = 21; - base = 125; + div = 16; break; default: return -1; } - return ((val - 0xbd) * mult) + base; + return DIV_ROUND_CLOSEST(ddr_freq * (val + 6 - 0xbd), 4 * div); } int vlv_freq_opcode(int ddr_freq, int val) { - int mult, base; + int mul; + /* 4 x czclk */ switch (ddr_freq) { case 800: - mult = 20; - base = 120; + mul = 10; break; case 1066: - mult = 22; - base = 133; + mul = 12; break; case 1333: - mult = 21; - base = 125; + mul = 16; break; default: return -1; } - val /= mult; - val -= base / mult; - val += 0xbd; - - if (val > 0xea) - val = 0xea; - - return val; + return DIV_ROUND_CLOSEST(4 * mul * val, ddr_freq) + 0xbd - 6; } void intel_pm_init(struct drm_device *dev)