Re: [PATCH 66/66] drm/i915: runtime PM support for DPMS

[Jesse Barnes <jbarnes@virtuousgeek.org>]

On Thu, 24 Apr 2014 23:55:42 +0200
Daniel Vetter <daniel.vetter@ffwll.ch> wrote:

> +	if (enable) {
> +		if (!intel_crtc->active) {
> +			domains = get_crtc_power_domains(crtc);
> +			for_each_power_domain(domain, domains)
> +				intel_display_power_get(dev_priv, domain);
> +			intel_crtc->enabled_power_domains = domains;
> +
> +			dev_priv->display.crtc_enable(crtc);
> +		}
> +	} else {
> +		if (intel_crtc->active) {
> +			dev_priv->display.crtc_disable(crtc);
> +
> +			domains = intel_crtc->enabled_power_domains;
> +			for_each_power_domain(domain, domains)
> +				intel_display_power_put(dev_priv, domain);
> +			intel_crtc->enabled_power_domains = 0;
> +		}
> +	}

These branches could probably be cleaned up a bit.

But the power domain bits here got me thinking that maybe we can push
them down into the crtc_enable/disable functions instead.  That would
let us do the right thing per-platform and save us the
"get_crtc_power_domains" call which may not make sense on all platforms.

I haven't thought it through for the other power wells, but that type
of approach may make more sense than trying to abstract the wells at
the high level we're doing today, especially since things are likely to
get finer grained over time rather than coarser.

-- 
Jesse Barnes, Intel Open Source Technology Center