Re: [Intel-gfx] [v2 0/7] Add Multi Segment Gamma Support

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Mon, Apr 08, 2019 at 12:26:23PM +0000, Shankar, Uma wrote:
> 
> 
> >-----Original Message-----
> >From: dri-devel [mailto:dri-devel-bounces@lists.freedesktop.org] On Behalf Of Ville
> >Syrjälä
> >Sent: Friday, April 5, 2019 9:42 PM
> >To: Shankar, Uma <uma.shankar@intel.com>
> >Cc: dcastagna@chromium.org; intel-gfx@lists.freedesktop.org; dri-
> >devel@lists.freedesktop.org; seanpaul@chromium.org; Syrjala, Ville
> ><ville.syrjala@intel.com>; Lankhorst, Maarten <maarten.lankhorst@intel.com>
> >Subject: Re: [Intel-gfx] [v2 0/7] Add Multi Segment Gamma Support
> >
> >On Mon, Apr 01, 2019 at 11:00:04PM +0530, Uma Shankar wrote:
> >> This series adds support for programmable gamma modes and exposes a
> >> property interface for the same. Also added, support for multi segment
> >> gamma mode introduced in ICL+
> >>
> >> It creates 2 property interfaces :
> >> 1. GAMMA_MODE_CAPS: This is immutable property and exposes the various
> >> gamma modes supported and the lut ranges. This is an enum property
> >> with element as blob id. Getting the blob id in userspace, user can
> >> get the mode supported and also the range of gamma mode supported with
> >> number of lut coefficients.
> >>
> >> 2. GAMMA_MODE: This is for user to set the gamma mode and send the lut
> >> values for that particular mode.
> >
> >I think we should just go for the BLOB_ENUM prop type instead.
> >Then the possible values and the current value are all part of the same prop.
> 
> Hi Ville,
> With the current approach, we have enum property with values as blob_ids 
> (representing platform capabilities). This should not get modified and needs to
> be immutable.

That's not quite what we want. We want to let the user modify the
current value so that they can actually select the gamma mode.
Otherwise we need yet another prop for it, or we have to deduce it
from the LUT size (that apporach would actually work for i915 but
may not work for other drivers/hardware).

> 
> Userspace can query the property and get the blob using the blob_ids. Thereby
> getting all the platform capabilities.
> 
> Now to set the LUT values, he can use another blob property and pass the
> luts.  This is inline to how gamma/degamma is implemented where we have
> one immutable LUT_SIZE property (indicating number of luts) and another blob
> property for actual lut values.
> 
> Regards,
> Uma Shankar
> 
> >>
> >> v2: Used Ville's design and approach to define the interfaces.
> >> Addressed Matt Roper's review feedback and re-ordered the patches.
> >>
> >> Uma Shankar (5):
> >>   drm: Add gamma mode property
> >>   drm/i915/icl: Add register definitions for Multi Segmented gamma
> >>   drm/i915/icl: Add support for multi segmented gamma mode
> >>   drm/i915: Add gamma mode caps property
> >>   drm/i915: Attach gamma mode property
> >>
> >> Ville Syrjälä (2):
> >>   drm: Add gamma mode caps property
> >>   drm/i915: Define color lut range structure
> >>
> >>  drivers/gpu/drm/drm_atomic_uapi.c    |  13 +
> >>  drivers/gpu/drm/drm_color_mgmt.c     | 110 +++++++++
> >>  drivers/gpu/drm/i915/i915_reg.h      |  17 ++
> >>  drivers/gpu/drm/i915/intel_color.c   | 465
> >++++++++++++++++++++++++++++++++++-
> >>  drivers/gpu/drm/i915/intel_display.c |   5 +
> >>  include/drm/drm_color_mgmt.h         |  11 +
> >>  include/drm/drm_crtc.h               |  17 ++
> >>  include/drm/drm_mode_config.h        |  10 +
> >>  include/uapi/drm/drm_mode.h          |  49 ++++
> >>  9 files changed, 690 insertions(+), 7 deletions(-)
> >>
> >> --
> >> 1.9.1
> >>
> >> _______________________________________________
> >> Intel-gfx mailing list
> >> Intel-gfx@lists.freedesktop.org
> >> https://lists.freedesktop.org/mailman/listinfo/intel-gfx
> >
> >--
> >Ville Syrjälä
> >Intel
> >_______________________________________________
> >dri-devel mailing list
> >dri-devel@lists.freedesktop.org
> >https://lists.freedesktop.org/mailman/listinfo/dri-devel

-- 
Ville Syrjälä
Intel
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