[Intel-gfx] [v6 0/2] Add Colorspace connector property interface

[Brian Starkey]

Hi Uma,

On Thu, Dec 27, 2018 at 11:22:36PM +0530, Uma Shankar wrote:
> This patch series creates a new connector property to program
> colorspace to sink devices. Modern sink devices support more
> than 1 type of colorspace like 601, 709, BT2020 etc. This helps
> to switch based on content type which is to be displayed. The
> decision lies with compositors as to in which scenarios, a
> particular colorspace will be picked.
> 
> This will be helpful mostly to switch to higher gamut colorspaces
> like BT2020 when the media content is encoded as BT2020. Thereby
> giving a good visual experience to users.
> 
> The expectation from userspace is that it should parse the EDID
> and get supported colorspaces. Use this property and switch to the
> one supported. Kernel will not give the supported colorspaces since
> this is panel dependent and our current property infrastructure is
> not supporting it.
> 
> Basically the expectation from userspace is:
>  - Set up CRTC DEGAMMA/CTM/GAMMA to convert to some sink
>    colorspace
>  - Set this new property to let the sink know what it
>    converted the CRTC output to.
>  - This property is just to inform sink what colorspace
>    source is trying to drive.

All the above info is really important/useful stuff, but it's going to
get lost because it's only in the cover letter. This should either
find its way into the commit message of patch 1 or even better, into
the kerneldoc for the property.

Cheers,
-Brian

> 
> Have tested this using xrandr by using below command:
> xrandr --output HDMI2 --set "Colorspace" "BT2020_rgb"
> 
> v2: Addressed Ville and Maarten's review comments. Merged the 2nd
> and 3rd patch into one common logical patch.
> 
> v3: Removed Adobe references from enum definitions as per
> Ville, Hans Verkuil and Jonas Karlman suggestions. Changed
> default to an unset state where driver will assign the colorspace
> when not chosen by user, suggested by Ville and Maarten. Addressed
> other misc review comments from Maarten. Split the changes to
> have separate colorspace property for DP and HDMI.
> 
> v4: Addressed Chris and Ville's review comments, and created a
> common colorspace property for DP and HDMI, filtered the list
> based on the colorspaces supported by the respective protocol
> standard. Handled the default case more efficiently.
> 
> v5: Modified the colorspace property creation helper to take
> platform specific enum list based on the capabilities of the
> platform as suggested by Shashank. With this there is no need
> for segregation between DP and HDMI.
> 
> v6: Addressed Shashank's review comments.
> 
> Uma Shankar (2):
>   drm: Add colorspace connector property
>   drm/i915: Attach colorspace property and enable modeset
> 
>  drivers/gpu/drm/drm_atomic_uapi.c      |  4 ++
>  drivers/gpu/drm/drm_connector.c        | 82 ++++++++++++++++++++++++++++++++++
>  drivers/gpu/drm/i915/intel_atomic.c    |  1 +
>  drivers/gpu/drm/i915/intel_connector.c | 63 ++++++++++++++++++++++++++
>  drivers/gpu/drm/i915/intel_drv.h       |  1 +
>  drivers/gpu/drm/i915/intel_hdmi.c      | 18 ++++++++
>  include/drm/drm_connector.h            | 17 +++++++
>  include/uapi/drm/drm_mode.h            | 33 ++++++++++++++
>  8 files changed, 219 insertions(+)
> 
> -- 
> 1.9.1
> 
> Uma Shankar (2):
>   drm: Add colorspace connector property
>   drm/i915: Attach colorspace property and enable modeset
> 
>  drivers/gpu/drm/drm_atomic_uapi.c      |  4 ++
>  drivers/gpu/drm/drm_connector.c        | 79 ++++++++++++++++++++++++++++++++++
>  drivers/gpu/drm/i915/intel_atomic.c    |  1 +
>  drivers/gpu/drm/i915/intel_connector.c | 63 +++++++++++++++++++++++++++
>  drivers/gpu/drm/i915/intel_drv.h       |  1 +
>  drivers/gpu/drm/i915/intel_hdmi.c      | 19 ++++++++
>  include/drm/drm_connector.h            | 17 ++++++++
>  include/uapi/drm/drm_mode.h            | 33 ++++++++++++++
>  8 files changed, 217 insertions(+)
> 
> -- 
> 1.9.1
>