[Intel-gfx] [v2 0/2] Add Colorspace connector property interface

[Sharma, Shashank]

Hello Uma,

My comments inline.


On 10/31/2018 5:35 PM, 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 curremt property infrastructure is
> not supporting it.
I am not very sure about this part, consider a situation where, I have 
connected a HDMI 2.0 monitor which supports BT2020 gamut, to a GEN9 
device, running an user-space which can also support BT2020 playback / 
HDR playback. Now, both monitor and user-space supports BT2020 playback, 
but the HW doesn't, and this will create a problem during playback. So I 
gess we need to expose a kernel Cap or property to showcase if the HW 
can support BT2020/DCI-P3 gamut space or not.

- Shashank
> 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.
>
> Uma Shankar (2):
>    drm: Add colorspace property
>    drm/i915: Attach colorspace property and enable modeset
>
>   drivers/gpu/drm/drm_atomic_uapi.c   |  4 ++++
>   drivers/gpu/drm/drm_connector.c     | 44 +++++++++++++++++++++++++++++++++++++
>   drivers/gpu/drm/i915/intel_atomic.c |  1 +
>   drivers/gpu/drm/i915/intel_hdmi.c   |  5 +++++
>   include/drm/drm_connector.h         |  7 ++++++
>   include/drm/drm_mode_config.h       |  6 +++++
>   include/uapi/drm/drm_mode.h         | 24 ++++++++++++++++++++
>   7 files changed, 91 insertions(+)
>