On Thu, 26 Sep 2013 23:25:46 +0100 Chris Wilson <ch...@chris-wilson.co.uk> wrote:
> On Thu, Sep 26, 2013 at 12:33:21PM -0700, Jesse Barnes wrote: > > We need to use the clock control reg to figure out how many CZ clks are in > > 30ns and use that as the basis for our RC6 residency calculations. > > Hmm, that was confusing. Took a couple of reads to be sure that the > specs said that the units were always CZ clock cycles. > > > References: https://bugs.freedesktop.org/show_bug.cgi?id=69692 > > Signed-off-by: Jesse Barnes <jbar...@virtuousgeek.org> > > --- > > drivers/gpu/drm/i915/i915_reg.h | 3 +++ > > drivers/gpu/drm/i915/i915_sysfs.c | 22 ++++++++++++++++++++-- > > 2 files changed, 23 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/gpu/drm/i915/i915_reg.h > > b/drivers/gpu/drm/i915/i915_reg.h > > index cf995bb..6f8d0cf 100644 > > --- a/drivers/gpu/drm/i915/i915_reg.h > > +++ b/drivers/gpu/drm/i915/i915_reg.h > > @@ -1797,6 +1797,9 @@ > > */ > > #define HSW_CXT_TOTAL_SIZE (17 * PAGE_SIZE) > > > > +#define VLV_CLK_CTL2 0x101104 > > +#define CLK_CTL2_CZCOUNT_30NS_SHIFT 28 > > + > > /* > > * Overlay regs > > */ > > diff --git a/drivers/gpu/drm/i915/i915_sysfs.c > > b/drivers/gpu/drm/i915/i915_sysfs.c > > index 44f4c1a..9c60515 100644 > > --- a/drivers/gpu/drm/i915/i915_sysfs.c > > +++ b/drivers/gpu/drm/i915/i915_sysfs.c > > @@ -37,12 +37,30 @@ 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 = 100 000ULL; > > The ULL suffix here are superfluous and I notice that you didn't use the > suffix for the later constants. Be consistent. > > Normal units = 128 / (100 * 1000), i.e. each unit is 1.28/1000ms I can drop the ULL, sure. > > > > > if (!intel_enable_rc6(dev)) > > return 0; > > > > - raw_time = I915_READ(reg) * 128ULL; > > - return DIV_ROUND_UP_ULL(raw_time, 100000); > > + /* On VLV, residency time is in CZ units rather than 1.28us */ > > + if (IS_VALLEYVIEW(dev)) { > > + u32 clkctl2; > > + > > + clkctl2 = I915_READ(VLV_CLK_CTL2) >> > > + CLK_CTL2_CZCOUNT_30NS_SHIFT; > > + if (!clkctl2) { > > + WARN(!clkctl2, "bogus CZ count value"); > > + return 0; > > + } > > + units = DIV_ROUND_UP_ULL(3000ULL, (u64)clkctl2); > > For your divisor, this should 30*1000 not 3*1000. 30ns * 100 for fixed point precision, just as above. > > > + if (I915_READ(VLV_COUNTER_CONTROL) & VLV_COUNT_RANGE_HIGH) > > + units <<= 8; > > + > > + div = 100 000 000; Then here we divide out the ns to ms (1000000) and also the 100 for fixed point. Or do I still have it wrong? -- Jesse Barnes, Intel Open Source Technology Center _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/intel-gfx
