Re: [PATCH 1/9] drm: Add gamma mode property
On Wed, 2 Jun 2021 20:18:19 + "Shankar, Uma" wrote: > > -Original Message- > > From: Pekka Paalanen > > Sent: Wednesday, June 2, 2021 2:40 PM > > To: Shankar, Uma > > Cc: intel-...@lists.freedesktop.org; dri-devel@lists.freedesktop.org; Modem, > > Bhanuprakash > > Subject: Re: [PATCH 1/9] drm: Add gamma mode property > > > > On Tue, 1 Jun 2021 16:11:27 +0530 > > Uma Shankar wrote: > > > > > Add a gamma mode property to enable various kind of gamma modes > > > supported by platforms like: Interpolated, Split, Multi Segmented, > > > Logarithmic etc. Userspace can get this property and should be able to > > > get the platform capabilities wrt various gamma modes possible and the > > > possible ranges. > > > > > > It can select one of the modes exposed as blob_id as an enum and set > > > the respective mode. > > > > > > It can then create the LUT and send it to driver using already > > > available GAMMA_LUT property as blob. > > > > > > Note: This is based on design by Ville and is being carried forward > > > based on his original idea. > > > > > > Signed-off-by: Uma Shankar > > > --- > > > drivers/gpu/drm/drm_atomic_uapi.c | 5 +++ > > > drivers/gpu/drm/drm_color_mgmt.c | 75 +++ > > > include/drm/drm_color_mgmt.h | 8 > > > include/drm/drm_crtc.h| 14 ++ > > > include/uapi/drm/drm_mode.h | 43 ++ > > > 5 files changed, 145 insertions(+) ... > > Hi, > > > > where is the UAPI documentation for this new GAMMA_MODE? > > As a userspace dev, I have no idea what to do with the above based on what's > > written here. > > Got that, I will add more details on the UAPI usage to make things a bit > clearer. > > > Also, reading the description of DRM_CLIENT_CAP_ADVANCE_GAMMA_MODES in > > patch 5/9, what difference does it make whether userspace sets or does not > > set that > > cap? I don't understand the implications from the description. > > The reason we have this Client caps is to have it co-exist with legacy crtc > color properties. > The idea is that driver will describe the h/w luts to userspace through > GAMMA_MODE UAPI, > but the actual lut samples will still be sent through the legacy GAMMA_LUT > UAPI. This client > cap will help distinguish between legacy and this new implementation. > > I will add more details in the UAPI description to avoid ambiguity and > explain the rationale and > usage of this UAPI. > > Thanks Pekka for the looking into the series and the initial feedback. Thanks a lot, will be interesting to read those docs. pq pgpX40QqOpQsH.pgp Description: OpenPGP digital signature
RE: [PATCH 1/9] drm: Add gamma mode property
> -Original Message-
> From: Pekka Paalanen
> Sent: Wednesday, June 2, 2021 2:40 PM
> To: Shankar, Uma
> Cc: intel-...@lists.freedesktop.org; dri-devel@lists.freedesktop.org; Modem,
> Bhanuprakash
> Subject: Re: [PATCH 1/9] drm: Add gamma mode property
>
> On Tue, 1 Jun 2021 16:11:27 +0530
> Uma Shankar wrote:
>
> > Add a gamma mode property to enable various kind of gamma modes
> > supported by platforms like: Interpolated, Split, Multi Segmented,
> > Logarithmic etc. Userspace can get this property and should be able to
> > get the platform capabilities wrt various gamma modes possible and the
> > possible ranges.
> >
> > It can select one of the modes exposed as blob_id as an enum and set
> > the respective mode.
> >
> > It can then create the LUT and send it to driver using already
> > available GAMMA_LUT property as blob.
> >
> > Note: This is based on design by Ville and is being carried forward
> > based on his original idea.
> >
> > Signed-off-by: Uma Shankar
> > ---
> > drivers/gpu/drm/drm_atomic_uapi.c | 5 +++
> > drivers/gpu/drm/drm_color_mgmt.c | 75 +++
> > include/drm/drm_color_mgmt.h | 8
> > include/drm/drm_crtc.h| 14 ++
> > include/uapi/drm/drm_mode.h | 43 ++
> > 5 files changed, 145 insertions(+)
> >
>
> ...
>
> > diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h index
> > 13eeba2a750a..b1eead03ebe8 100644
> > --- a/include/drm/drm_crtc.h
> > +++ b/include/drm/drm_crtc.h
> > @@ -262,6 +262,13 @@ struct drm_crtc_state {
> > */
> > struct drm_property_blob *mode_blob;
> >
> > + /**
> > +* @gamma_mode: This is a blob_id and exposes the platform capabilities
> > +* wrt to various gamma modes and the respective lut ranges. This also
> > +* helps user select a gamma mode amongst the supported ones.
> > +*/
> > + u32 gamma_mode;
> > +
> > /**
> > * @degamma_lut:
> > *
> > @@ -1096,6 +1103,13 @@ struct drm_crtc {
> > */
> > struct drm_property *scaling_filter_property;
> >
> > + /**
> > +* @gamma_mode_property: Optional CRTC property to enumerate and
> > +* select the mode of the crtc gamma/degmama LUTs. This also exposes
> > +* the lut ranges of the various supported gamma modes to userspace.
> > +*/
> > + struct drm_property *gamma_mode_property;
> > +
> > /**
> > * @state:
> > *
> > diff --git a/include/uapi/drm/drm_mode.h b/include/uapi/drm/drm_mode.h
> > index 9b6722d45f36..d7758d351936 100644
> > --- a/include/uapi/drm/drm_mode.h
> > +++ b/include/uapi/drm/drm_mode.h
> > @@ -819,6 +819,49 @@ struct hdr_output_metadata {
> > };
> > };
> >
> > +/*
> > + * DRM_MODE_LUT_GAMMA|DRM_MODE_LUT_DEGAMMA is legal and means
> the LUT
> > + * can be used for either purpose, but not simultaneously. To expose
> > + * modes that support gamma and degamma simultaneously the gamma mode
> > + * must declare distinct DRM_MODE_LUT_GAMMA and
> DRM_MODE_LUT_DEGAMMA
> > + * ranges.
> > + */
> > +/* LUT is for gamma (after CTM) */
> > +#define DRM_MODE_LUT_GAMMA BIT(0)
> > +/* LUT is for degamma (before CTM) */ #define DRM_MODE_LUT_DEGAMMA
> > +BIT(1)
> > +/* linearly interpolate between the points */ #define
> > +DRM_MODE_LUT_INTERPOLATE BIT(2)
> > +/*
> > + * the last value of the previous range is the
> > + * first value of the current range.
> > + */
> > +#define DRM_MODE_LUT_REUSE_LAST BIT(3)
> > +/* the curve must be non-decreasing */ #define
> > +DRM_MODE_LUT_NON_DECREASING BIT(4)
> > +/* the curve is reflected across origin for negative inputs */
> > +#define DRM_MODE_LUT_REFLECT_NEGATIVE BIT(5)
> > +/* the same curve (red) is used for blue and green channels as well
> > +*/ #define DRM_MODE_LUT_SINGLE_CHANNEL BIT(6)
> > +
> > +struct drm_color_lut_range {
> > + /* DRM_MODE_LUT_* */
> > + __u32 flags;
> > + /* number of points on the curve */
> > + __u16 count;
> > + /* input/output bits per component */
> > + __u8 input_bpc, output_bpc;
> > + /* input start/end values */
> > + __s32 start, end;
> > + /* output min/max values */
> > + __s32 min, max;
> > +};
> > +
> > +enum lut_type {
> > + LUT_TYPE_DEGAMMA = 0,
> > + LUT_TYPE_GAMMA = 1,
> > +};
> > +
> > #define DRM_MODE_PAGE_FLIP_EVENT 0x01
Re: [PATCH 1/9] drm: Add gamma mode property
On Tue, 1 Jun 2021 16:11:27 +0530
Uma Shankar wrote:
> Add a gamma mode property to enable various kind of
> gamma modes supported by platforms like: Interpolated, Split,
> Multi Segmented, Logarithmic etc. Userspace can get this property
> and should be able to get the platform capabilities wrt various
> gamma modes possible and the possible ranges.
>
> It can select one of the modes exposed as blob_id as an
> enum and set the respective mode.
>
> It can then create the LUT and send it to driver using
> already available GAMMA_LUT property as blob.
>
> Note: This is based on design by Ville and is being carried forward
> based on his original idea.
>
> Signed-off-by: Uma Shankar
> ---
> drivers/gpu/drm/drm_atomic_uapi.c | 5 +++
> drivers/gpu/drm/drm_color_mgmt.c | 75 +++
> include/drm/drm_color_mgmt.h | 8
> include/drm/drm_crtc.h| 14 ++
> include/uapi/drm/drm_mode.h | 43 ++
> 5 files changed, 145 insertions(+)
>
...
> diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
> index 13eeba2a750a..b1eead03ebe8 100644
> --- a/include/drm/drm_crtc.h
> +++ b/include/drm/drm_crtc.h
> @@ -262,6 +262,13 @@ struct drm_crtc_state {
>*/
> struct drm_property_blob *mode_blob;
>
> + /**
> + * @gamma_mode: This is a blob_id and exposes the platform capabilities
> + * wrt to various gamma modes and the respective lut ranges. This also
> + * helps user select a gamma mode amongst the supported ones.
> + */
> + u32 gamma_mode;
> +
> /**
>* @degamma_lut:
>*
> @@ -1096,6 +1103,13 @@ struct drm_crtc {
>*/
> struct drm_property *scaling_filter_property;
>
> + /**
> + * @gamma_mode_property: Optional CRTC property to enumerate and
> + * select the mode of the crtc gamma/degmama LUTs. This also exposes
> + * the lut ranges of the various supported gamma modes to userspace.
> + */
> + struct drm_property *gamma_mode_property;
> +
> /**
>* @state:
>*
> diff --git a/include/uapi/drm/drm_mode.h b/include/uapi/drm/drm_mode.h
> index 9b6722d45f36..d7758d351936 100644
> --- a/include/uapi/drm/drm_mode.h
> +++ b/include/uapi/drm/drm_mode.h
> @@ -819,6 +819,49 @@ struct hdr_output_metadata {
> };
> };
>
> +/*
> + * DRM_MODE_LUT_GAMMA|DRM_MODE_LUT_DEGAMMA is legal and means the LUT
> + * can be used for either purpose, but not simultaneously. To expose
> + * modes that support gamma and degamma simultaneously the gamma mode
> + * must declare distinct DRM_MODE_LUT_GAMMA and DRM_MODE_LUT_DEGAMMA
> + * ranges.
> + */
> +/* LUT is for gamma (after CTM) */
> +#define DRM_MODE_LUT_GAMMA BIT(0)
> +/* LUT is for degamma (before CTM) */
> +#define DRM_MODE_LUT_DEGAMMA BIT(1)
> +/* linearly interpolate between the points */
> +#define DRM_MODE_LUT_INTERPOLATE BIT(2)
> +/*
> + * the last value of the previous range is the
> + * first value of the current range.
> + */
> +#define DRM_MODE_LUT_REUSE_LAST BIT(3)
> +/* the curve must be non-decreasing */
> +#define DRM_MODE_LUT_NON_DECREASING BIT(4)
> +/* the curve is reflected across origin for negative inputs */
> +#define DRM_MODE_LUT_REFLECT_NEGATIVE BIT(5)
> +/* the same curve (red) is used for blue and green channels as well */
> +#define DRM_MODE_LUT_SINGLE_CHANNEL BIT(6)
> +
> +struct drm_color_lut_range {
> + /* DRM_MODE_LUT_* */
> + __u32 flags;
> + /* number of points on the curve */
> + __u16 count;
> + /* input/output bits per component */
> + __u8 input_bpc, output_bpc;
> + /* input start/end values */
> + __s32 start, end;
> + /* output min/max values */
> + __s32 min, max;
> +};
> +
> +enum lut_type {
> + LUT_TYPE_DEGAMMA = 0,
> + LUT_TYPE_GAMMA = 1,
> +};
> +
> #define DRM_MODE_PAGE_FLIP_EVENT 0x01
> #define DRM_MODE_PAGE_FLIP_ASYNC 0x02
> #define DRM_MODE_PAGE_FLIP_TARGET_ABSOLUTE 0x4
Hi,
where is the UAPI documentation for this new GAMMA_MODE?
As a userspace dev, I have no idea what to do with the above based on
what's written here.
Also, reading the description of DRM_CLIENT_CAP_ADVANCE_GAMMA_MODES in
patch 5/9, what difference does it make whether userspace sets or does
not set that cap? I don't understand the implications from the
description.
Thanks,
pq
pgpz0DTu2iUKf.pgp
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