[PATCH weston 1/9] compositor-drm: drm_output_enable updates unused_crtcs/connectors

[Daniel Stone]

Hi Pekka,

On 9 February 2018 at 13:07, Pekka Paalanen <ppaalanen at gmail.com> wrote:
> Let drm_output_enable() remove the CRTC and the connector from the
> unused id arrays.
>
> In the future when a list of drm_heads supersedes unused_connectors
> array, the usedness of a connector will be determined by the enabled
> state of the output the connector (head) is attached to. The enabled
> state is turned on by drm_output_enable(). If unused_crtcs array was
> still updated in drm_output_repaint(), the CRTC and connector usedness
> would be tracked in different places. Logically the two belong together.

I agree that when we have heads/connectors, this is logically the
right thing to do. This patch does reflexively make me a little uneasy
though: it relies on the repaint loop successfully completing before
the next repaint flush. The reason I moved the unused ID removal to
the bottom of repaint, is because that's the first point at which we
know (within reason) that repaint will succeed.

On the other hand, if repaint fails the output pretty much just wedges
forever anyway. So even though I'm kind of wary of this first one and
get the feeling we might end up revisiting it, I don't think it makes
things worse, and hopefully clone-mode makes it completely obsolete
anyway.

Bar a couple of minor nitpicks, series is:
Reviewed-by: Daniel Stone <daniels at collabora.com>

Cheers,
Daniel