[Intel-gfx] [PATCH] drm/i915: compute masks of crtcs affected in set_mode

[Jesse Barnes]

On Wed, 29 Aug 2012 12:34:04 +0200
Daniel Vetter <daniel.vetter at ffwll.ch> wrote:

> This is definetely a bit more generic than currently required, but
> if we keep track of all crtcs that need to be disabled/enable (because
> they loose an encoder or something similar), crtcs that get completely
> disabled and those that we need to do an actual mode change on nicely
> prepares us for global modeset operations on multiple crtcs.
> 
> The only big thing missing here would be a global resource allocation
> step (for e.g. pch plls), which would equally frob these bitmasks if
> e.g. a crtc only needs a new pll.
> 
> These masks aren't yet put to use in this patch, this will follow in the
> next one.
> 
> v2-v5: Fix up the computations for good (hopefully).
> 
> v6: Fixup a confusion reported by Damien Lespiau: I've conserved the
> (imo braindead) behaviour of the crtc helper to disable _any_
> disconnected outputs if we do a modeset, even when that newly disabled
> connector isn't connected to the crtc being changed by the modeset.
> 
> The effect of that is that we could disable an arbitrary number of
> unrelated crtcs, which I haven't taken into account when writing this
> code. Fix this up.

Might not need to clean it up here though, since the only time that
should matter is during the first mode set after a power on or resume
when a superfluous CRTC might be enabled.  And with the new hw state
readout, we can fix that up.

You choose though.

Reviewed-by: Jesse Barnes <jbarnes at virtuousgeek.org>

-- 
Jesse Barnes, Intel Open Source Technology Center