[Intel-gfx] [RFC 02/11] drm/i915: Add intel_energy_uJ

[Chris Wilson]

Quoting Tvrtko Ursulin (2017-09-15 07:56:00)
> 
> On 14/09/2017 21:36, Ville Syrjälä wrote:
> > On Mon, Sep 11, 2017 at 04:25:50PM +0100, Tvrtko Ursulin wrote:
> >> From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> >>
> >> Extract code from i915_energy_uJ (debugfs) so it can be used by
> >> other callers in future patches.
> >>
> >> v2: Rebase.
> >>
> >> Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> >> ---
> >>   drivers/gpu/drm/i915/i915_debugfs.c | 17 +----------------
> >>   drivers/gpu/drm/i915/i915_drv.h     |  2 ++
> >>   drivers/gpu/drm/i915/intel_pm.c     | 25 +++++++++++++++++++++++++
> >>   3 files changed, 28 insertions(+), 16 deletions(-)
> >>
> >> diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
> >> index 6338018f655d..b3a4a66bf7c4 100644
> >> --- a/drivers/gpu/drm/i915/i915_debugfs.c
> >> +++ b/drivers/gpu/drm/i915/i915_debugfs.c
> >> @@ -2780,26 +2780,11 @@ static int i915_sink_crc(struct seq_file *m, void *data)
> >>   static int i915_energy_uJ(struct seq_file *m, void *data)
> >>   {
> >>      struct drm_i915_private *dev_priv = node_to_i915(m->private);
> >> -    unsigned long long power;
> >> -    u32 units;
> >>   
> >>      if (INTEL_GEN(dev_priv) < 6)
> >>              return -ENODEV;
> >>   
> >> -    intel_runtime_pm_get(dev_priv);
> >> -
> >> -    if (rdmsrl_safe(MSR_RAPL_POWER_UNIT, &power)) {
> >> -            intel_runtime_pm_put(dev_priv);
> >> -            return -ENODEV;
> >> -    }
> >> -
> >> -    units = (power & 0x1f00) >> 8;
> >> -    power = I915_READ(MCH_SECP_NRG_STTS);
> >> -    power = (1000000 * power) >> units; /* convert to uJ */
> >> -
> >> -    intel_runtime_pm_put(dev_priv);
> >> -
> >> -    seq_printf(m, "%llu", power);
> >> +    seq_printf(m, "%llu", intel_energy_uJ(dev_priv));
> > 
> > Isn't this the same thing as the package energy you get from rapl? Can't
> > we just nuke this private implementation entirely and rely on whatever
> > rapl gives us?
> 
> If so I think we could leave it out of i915 PMU. I tried looking for 
> MCH_SECP_NRG_STTS in bspec but did not find it though? Is your bspec fu 
> perhaps better and you could have a look?

I had it there for the convenience of grabbing everything through the
one interface (which I still think has merit). I don't I ever compiled
in the rapl user interface...
-Chris