[Intel-gfx] [PATCH 6/6] DRAFT: drm/i915: do adapter power state notification on PC8+ enable/disable

[Paulo Zanoni]

2013/8/23 Jani Nikula <jani.nikula at intel.com>:

/* Please insert explanation on why we need this and what changes if
we do this. */

I applied your patches and booted them. I got into PC8, did the PC8
test suite and nothing changed. I really don't know what to expect
from this series and/or how to check what's improving. Also, see
below:


> Signed-off-by: Jani Nikula <jani.nikula at intel.com>
> ---
>  drivers/gpu/drm/i915/intel_display.c |    4 ++++
>  1 file changed, 4 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index a6df68e..7ed2248 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -6093,6 +6093,8 @@ void hsw_enable_pc8_work(struct work_struct *__work)
>         lpt_disable_clkout_dp(dev);
>         hsw_pc8_disable_interrupts(dev);
>         hsw_disable_lcpll(dev_priv, true, true);
> +
> +       intel_opregion_notify_adapter(dev, PCI_D1);

Why D1? Shouldn't this be D3? I think that's what people having been
asking us to implement.

On the doc that explains "adapter power state notification", my
understanding is that it suggests that we should call this _before_ we
go into the lower states and the other chunk should be called _after_
we're at the higher power states. So perhaps we should call
intel_opregion_notify_adapter before hsw_disable_lcpll, and, on the
chunk below, after hsw_restore_lcpll? But this is not 100% clear, I
may be wrong.

By the way, I modified your patch to implement the suggestions above,
and got the same results: no noticeable difference, everything still
works. No news is good news?


>  }
>
>  static void __hsw_enable_package_c8(struct drm_i915_private *dev_priv)
> @@ -6126,6 +6128,8 @@ static void __hsw_disable_package_c8(struct drm_i915_private *dev_priv)
>         if (!dev_priv->pc8.enabled)
>                 return;
>
> +       intel_opregion_notify_adapter(dev, PCI_D0);
> +
>         DRM_DEBUG_KMS("Disabling package C8+\n");
>
>         hsw_restore_lcpll(dev_priv);
> --
> 1.7.9.5
>



-- 
Paulo Zanoni