Re: [RFC PATCH 12/40] drm/amd/display: add plane HDR multiplier driver-private property

From: Melissa Wen
Date: Tue May 09 2023 - 12:37:16 EST


On 05/08, Harry Wentland wrote:
>
>
> On 4/23/23 10:10, Melissa Wen wrote:
> > From: Joshua Ashton <joshua@xxxxxxxxx>
> >
> > Multiplier to 'gain' the plane. When PQ is decoded using the fixed func
> > transfer function to the internal FP16 fb, 1.0 -> 80 nits (on AMD at
> > least) When sRGB is decoded, 1.0 -> 1.0. Therefore, 1.0 multiplier = 80
> > nits for SDR content. So if you want, 203 nits for SDR content, pass in
> > (203.0 / 80.0).
> >
>
> Is gamescope intending to use this?

I don't think so. Again, I'll double check and drop it accordingly.

Melissa

>
> Harry
>
> > Co-developed-by: Melissa Wen <mwen@xxxxxxxxxx>
> > Signed-off-by: Melissa Wen <mwen@xxxxxxxxxx>
> > Signed-off-by: Joshua Ashton <joshua@xxxxxxxxx>
> > ---
> > drivers/gpu/drm/amd/amdgpu/amdgpu_display.c | 6 +++++
> > drivers/gpu/drm/amd/amdgpu/amdgpu_mode.h | 4 +++
> > .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h | 12 +++++++++
> > .../amd/display/amdgpu_dm/amdgpu_dm_plane.c | 25 ++++++++++++++-----
> > 4 files changed, 41 insertions(+), 6 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c
> > index 24595906dab1..dd658f162f6f 100644
> > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c
> > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c
> > @@ -1326,6 +1326,12 @@ amdgpu_display_create_color_properties(struct amdgpu_device *adev)
> > return -ENOMEM;
> > adev->mode_info.plane_degamma_tf_property = prop;
> >
> > + prop = drm_property_create_range(adev_to_drm(adev),
> > + 0, "AMD_PLANE_HDR_MULT", 0, UINT_MAX);
> > + if (!prop)
> > + return -ENOMEM;
> > + adev->mode_info.plane_hdr_mult_property = prop;
> > +
> > return 0;
> > }
> > #endif
> > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_mode.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_mode.h
> > index ab9ce6f26c90..65a9d62ffbe4 100644
> > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_mode.h
> > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_mode.h
> > @@ -387,6 +387,10 @@ struct amdgpu_mode_info {
> > * linearize content with or without LUT.
> > */
> > struct drm_property *plane_degamma_tf_property;
> > + /**
> > + * @plane_hdr_mult_property:
> > + */
> > + struct drm_property *plane_hdr_mult_property;
> > #endif
> > };
> >
> > diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
> > index 005632c1c9ec..bb7307b9cfd5 100644
> > --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
> > +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
> > @@ -51,6 +51,7 @@
> >
> > #define AMDGPU_DMUB_NOTIFICATION_MAX 5
> >
> > +#define AMDGPU_HDR_MULT_DEFAULT (0x100000000LL)
> > /*
> > #include "include/amdgpu_dal_power_if.h"
> > #include "amdgpu_dm_irq.h"
> > @@ -736,6 +737,17 @@ struct dm_plane_state {
> > * linearize.
> > */
> > enum drm_transfer_function degamma_tf;
> > + /**
> > + * @hdr_mult:
> > + *
> > + * Multiplier to 'gain' the plane. When PQ is decoded using the fixed
> > + * func transfer function to the internal FP16 fb, 1.0 -> 80 nits (on
> > + * AMD at least). When sRGB is decoded, 1.0 -> 1.0, obviously.
> > + * Therefore, 1.0 multiplier = 80 nits for SDR content. So if you
> > + * want, 203 nits for SDR content, pass in (203.0 / 80.0). Format is
> > + * S31.32 sign-magnitude.
> > + */
> > + __u64 hdr_mult;
> > #endif
> > };
> >
> > diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_plane.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_plane.c
> > index 5b458cc0781c..57169dae8b3d 100644
> > --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_plane.c
> > +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_plane.c
> > @@ -1321,8 +1321,10 @@ static void dm_drm_plane_reset(struct drm_plane *plane)
> > __drm_atomic_helper_plane_reset(plane, &amdgpu_state->base);
> >
> > #ifdef CONFIG_STEAM_DECK
> > - if (amdgpu_state)
> > + if (amdgpu_state) {
> > amdgpu_state->degamma_tf = DRM_TRANSFER_FUNCTION_DEFAULT;
> > + amdgpu_state->hdr_mult = AMDGPU_HDR_MULT_DEFAULT;
> > + }
> > #endif
> > }
> >
> > @@ -1424,11 +1426,11 @@ static void dm_drm_plane_destroy_state(struct drm_plane *plane,
> > #ifdef CONFIG_STEAM_DECK
> > int
> > amdgpu_dm_replace_property_blob_from_id(struct drm_device *dev,
> > - struct drm_property_blob **blob,
> > - uint64_t blob_id,
> > - ssize_t expected_size,
> > - ssize_t expected_elem_size,
> > - bool *replaced)
> > + struct drm_property_blob **blob,
> > + uint64_t blob_id,
> > + ssize_t expected_size,
> > + ssize_t expected_elem_size,
> > + bool *replaced)
> > {
> > struct drm_property_blob *new_blob = NULL;
> >
> > @@ -1482,6 +1484,10 @@ dm_plane_attach_color_mgmt_properties(struct amdgpu_display_manager *dm,
> > dm->adev->mode_info.plane_degamma_tf_property,
> > DRM_TRANSFER_FUNCTION_DEFAULT);
> > }
> > + /* HDR MULT is always available */
> > + drm_object_attach_property(&plane->base,
> > + dm->adev->mode_info.plane_hdr_mult_property,
> > + AMDGPU_HDR_MULT_DEFAULT);
> > }
> >
> > static int
> > @@ -1507,6 +1513,11 @@ dm_atomic_plane_set_property(struct drm_plane *plane,
> > dm_plane_state->degamma_tf = val;
> > dm_plane_state->base.color_mgmt_changed = 1;
> > }
> > + } else if (property == adev->mode_info.plane_hdr_mult_property) {
> > + if (dm_plane_state->hdr_mult != val) {
> > + dm_plane_state->hdr_mult = val;
> > + dm_plane_state->base.color_mgmt_changed = 1;
> > + }
> > } else {
> > drm_dbg_atomic(plane->dev,
> > "[PLANE:%d:%s] unknown property [PROP:%d:%s]]\n",
> > @@ -1533,6 +1544,8 @@ dm_atomic_plane_get_property(struct drm_plane *plane,
> > dm_plane_state->degamma_lut->base.id : 0;
> > } else if (property == adev->mode_info.plane_degamma_tf_property) {
> > *val = dm_plane_state->degamma_tf;
> > + } else if (property == adev->mode_info.plane_hdr_mult_property) {
> > + *val = dm_plane_state->hdr_mult;
> > } else {
> > return -EINVAL;
> > }
>
>

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