[PATCH v6 1/3] drm: Add CRTC background color property (v5)

[Matt Roper]

On Thu, Apr 25, 2019 at 12:45:33PM +0200, Maarten Lankhorst wrote:
> Op 26-02-2019 om 17:17 schreef Matt Roper:
> > On Tue, Feb 26, 2019 at 08:26:36AM +0100, Maarten Lankhorst wrote:
> >> Hey,
> >>
> >> Op 21-02-2019 om 01:28 schreef Matt Roper:
> >>> Some display controllers can be programmed to present non-black colors
> >>> for pixels not covered by any plane (or pixels covered by the
> >>> transparent regions of higher planes).  Compositors that want a UI with
> >>> a solid color background can potentially save memory bandwidth by
> >>> setting the CRTC background property and using smaller planes to display
> >>> the rest of the content.
> >>>
> >>> To avoid confusion between different ways of encoding RGB data, we
> >>> define a standard 64-bit format that should be used for this property's
> >>> value.  Helper functions and macros are provided to generate and dissect
> >>> values in this standard format with varying component precision values.
> >>>
> >>> v2:
> >>>  - Swap internal representation's blue and red bits to make it easier
> >>>    to read if printed out.  (Ville)
> >>>  - Document bgcolor property in drm_blend.c.  (Sean Paul)
> >>>  - s/background_color/bgcolor/ for consistency between property name and
> >>>    value storage field.  (Sean Paul)
> >>>  - Add a convenience function to attach property to a given crtc.
> >>>
> >>> v3:
> >>>  - Restructure ARGB component extraction macros to be easier to
> >>>    understand and enclose the parameters in () to avoid calculations
> >>>    if expressions are passed.  (Sean Paul)
> >>>  - s/rgba/argb/ in helper function/macro names.  Even though the idea is
> >>>    to not worry about the internal representation of the u64, it can
> >>>    still be confusing to look at code that uses 'rgba' terminology, but
> >>>    stores values with argb ordering.  (Ville)
> >>>
> >>> v4:
> >>>  - Drop the bgcolor_changed flag.  (Ville, Brian Starkey)
> >>>  - Clarify in kerneldoc that background color is expected to undergo the
> >>>    same pipe-level degamma/csc/gamma transformations that planes do.
> >>>    (Brian Starkey)
> >>>  - Update kerneldoc to indicate non-opaque colors are allowed, but are
> >>>    generally only useful in special cases such as when writeback
> >>>    connectors are used (Brian Starkey / Eric Anholt)
> >>>
> >>> v5:
> >>>  - Set crtc->state->bgcolor to solid black inside
> >>>    drm_crtc_add_bgcolor_property() in case drivers don't do this
> >>>    themselves.  (Ville)
> >>>  - Add kerneldoc to drm_crtc_add_bgcolor_property() function.
> >>>
> >>> Cc: dri-devel at lists.freedesktop.org
> >>> Cc: wei.c.li at intel.com
> >>> Cc: harish.krupo.kps at intel.com
> >>> Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> >>> Cc: Sean Paul <sean at poorly.run>
> >>> Cc: Brian Starkey <Brian.Starkey at arm.com>
> >>> Cc: Eric Anholt <eric at anholt.net>
> >>> Cc: Stéphane Marchesin <marcheu at chromium.org>
> >>> Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
> >>> Signed-off-by: Matt Roper <matthew.d.roper at intel.com>
> >>> Reviewed-by(v2): Sean Paul <sean at poorly.run>
> >>> Reviewed-by: Brian Starkey <brian.starkey at arm.com>
> >> I like how bgcolor is a u64 now, but there is an issue with setting
> >> crtc->state->bgcolor in attaching the property.
> >>
> >> We should do it in atomic core init instead, like we already do for
> >> connector/plane properties..
> >>
> >> See for example https://patchwork.freedesktop.org/series/52363/
> >>
> >> This was specificallly for the background color proposal, but we
> >> probalby have to split out the non-trivial conversions of
> >> __drm_atomic_helper_crtc_reset.
> > Makes sense.  What's the status of that patch?  It looks like it has a
> > lot of a-b's/r-b's but hasn't landed yet.  Is there anything blocking
> > it?  If you're still driving it forward, I can wait for that to land and
> > then build on top of it.
> >
> >
> > Matt
> >
> I've split out the patch and landed some of the preparation patches, it should be good enough to unblock this patch series at least now. :)
> 

Great, thanks!  I've been traveling a bunch the last month and haven't
had time to revisit this yet, but I'll come back and rebase / repost the
series in the next week or so once I'm caught up again.


Matt

-- 
Matt Roper
Graphics Software Engineer
IoTG Platform Enabling & Development
Intel Corporation
(916) 356-2795