On Mon, Jan 02, 2017 at 05:56:51PM +0200, Ville Syrjälä wrote: > On Mon, Jan 02, 2017 at 03:28:45PM +0000, Chris Wilson wrote: > > Ville explained that the wakelock was being acquired during set-idle in > > order to flush the voltage change from the punit. > > > > Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> > > Cc: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx > > --- > > drivers/gpu/drm/i915/intel_pm.c | 14 ++++++++++++-- > > 1 file changed, 12 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c > > index 4406359c5f81..4c9a1b12dfee 100644 > > --- a/drivers/gpu/drm/i915/intel_pm.c > > +++ b/drivers/gpu/drm/i915/intel_pm.c > > @@ -5011,8 +5011,18 @@ static void vlv_set_rps_idle(struct drm_i915_private *dev_priv) > > if (dev_priv->rps.cur_freq <= val) > > return; > > > > - /* Wake up the media well, as that takes a lot less > > - * power than the Render well. */ > > + /* The punit delays the write of the frequency and voltage until it > > + * determines the GPU is awake. During normal usage we don't want to > > + * waste power changing the frequency if the GPU is sleeping (rc6). > > + * However, the GPU and driver is now idle and we do not want to delay > > + * switching to minimum voltage (reducing power whilst idle) as we do > > + * not expect to be woken in the near future and so must flush the > > + * change by waking the device. > > + * > > + * We choose to take the media powerwell (either would do to trick the > > + * punit into commiting the voltage change) as that takes a lot less > > + * power than the render powerwell. > > + */ > > lgtm > > Reviewed-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> Ta, fixed a spelling mistake and pushed. -Chris -- Chris Wilson, Intel Open Source Technology Centre _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
