drm/amd/display: Rework CRTC color management

[Why]
To prepare for the upcoming DRM plane color management properties
we need to correct a lot of wrong behavior and assumptions made for
CRTC color management.

The documentation added by this commit in amdgpu_dm_color explains
how the HW color pipeline works and its limitations with the DRM
interface.

The current implementation does the following wrong:
- Implicit sRGB DGM when no CRTC DGM is set
- Implicit sRGB RGM when no CRTC RGM is set
- No way to specify a non-linear DGM matrix that produces correct output
- No way to specify a correct RGM when a linear DGM is used

We had workarounds for passing kms_color tests but not all of the
behavior we had wrong was covered by these tests (especially when
it comes to non-linear DGM). Testing both DGM and RGM at the same time
isn't something kms_color tests well either.

[How]
The specifics for how color management works in AMDGPU and the new
behavior can be found by reading the documentation added to
amdgpu_dm_color.c from this patch.

All of the incorrect cases from the old implementation have been
addressed for the atomic interface, but there still a few TODOs for
the legacy one.

Note: this does cause regressions for kms_color@pipe-a-ctm-* over HDMI.

The result looks correct from visual inspection but the CRC no longer
matches. For reference, the test was previously doing the following:

linear degamma -> CTM -> sRGB regamma -> RGB to YUV (709) -> ...

Now the test is doing:

linear degamma -> CTM -> linear regamma -> RGB to YUV (709) -> ...

Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Reviewed-by: Sun peng Li <Sunpeng.Li@amd.com>
Acked-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
This commit is contained in:
Nicholas Kazlauskas 2019-05-09 12:14:58 -04:00 committed by Alex Deucher
parent 1760bd06c8
commit 7cd4b70091
3 changed files with 357 additions and 160 deletions

View File

@ -2857,6 +2857,7 @@ static int fill_dc_plane_attributes(struct amdgpu_device *adev,
struct drm_plane_state *plane_state,
struct drm_crtc_state *crtc_state)
{
struct dm_crtc_state *dm_crtc_state = to_dm_crtc_state(crtc_state);
const struct amdgpu_framebuffer *amdgpu_fb =
to_amdgpu_framebuffer(plane_state->fb);
struct dc_scaling_info scaling_info;
@ -2901,13 +2902,11 @@ static int fill_dc_plane_attributes(struct amdgpu_device *adev,
* Always set input transfer function, since plane state is refreshed
* every time.
*/
ret = amdgpu_dm_set_degamma_lut(crtc_state, dc_plane_state);
if (ret) {
dc_transfer_func_release(dc_plane_state->in_transfer_func);
dc_plane_state->in_transfer_func = NULL;
}
ret = amdgpu_dm_update_plane_color_mgmt(dm_crtc_state, dc_plane_state);
if (ret)
return ret;
return ret;
return 0;
}
static void update_stream_scaling_settings(const struct drm_display_mode *mode,
@ -3482,6 +3481,8 @@ dm_crtc_duplicate_state(struct drm_crtc *crtc)
state->vrr_supported = cur->vrr_supported;
state->freesync_config = cur->freesync_config;
state->crc_enabled = cur->crc_enabled;
state->cm_has_degamma = cur->cm_has_degamma;
state->cm_is_degamma_srgb = cur->cm_is_degamma_srgb;
/* TODO Duplicate dc_stream after objects are stream object is flattened */
@ -5643,8 +5644,18 @@ static void amdgpu_dm_commit_planes(struct drm_atomic_state *state,
bundle->stream_update.dst = acrtc_state->stream->dst;
}
if (new_pcrtc_state->color_mgmt_changed)
bundle->stream_update.out_transfer_func = acrtc_state->stream->out_transfer_func;
if (new_pcrtc_state->color_mgmt_changed) {
/*
* TODO: This isn't fully correct since we've actually
* already modified the stream in place.
*/
bundle->stream_update.gamut_remap =
&acrtc_state->stream->gamut_remap_matrix;
bundle->stream_update.output_csc_transform =
&acrtc_state->stream->csc_color_matrix;
bundle->stream_update.out_transfer_func =
acrtc_state->stream->out_transfer_func;
}
acrtc_state->stream->abm_level = acrtc_state->abm_level;
if (acrtc_state->abm_level != dm_old_crtc_state->abm_level)
@ -6494,10 +6505,9 @@ static int dm_update_crtc_state(struct amdgpu_display_manager *dm,
*/
if (dm_new_crtc_state->base.color_mgmt_changed ||
drm_atomic_crtc_needs_modeset(new_crtc_state)) {
ret = amdgpu_dm_set_regamma_lut(dm_new_crtc_state);
ret = amdgpu_dm_update_crtc_color_mgmt(dm_new_crtc_state);
if (ret)
goto fail;
amdgpu_dm_set_ctm(dm_new_crtc_state);
}
/* Update Freesync settings. */
@ -6792,6 +6802,8 @@ dm_determine_update_type_for_commit(struct amdgpu_display_manager *dm,
new_dm_plane_state->dc_state->in_transfer_func;
stream_update.gamut_remap =
&new_dm_crtc_state->stream->gamut_remap_matrix;
stream_update.output_csc_transform =
&new_dm_crtc_state->stream->csc_color_matrix;
stream_update.out_transfer_func =
new_dm_crtc_state->stream->out_transfer_func;
}

View File

@ -271,6 +271,9 @@ struct dm_crtc_state {
struct drm_crtc_state base;
struct dc_stream_state *stream;
bool cm_has_degamma;
bool cm_is_degamma_srgb;
int active_planes;
bool interrupts_enabled;
@ -360,10 +363,9 @@ void amdgpu_dm_crtc_handle_crc_irq(struct drm_crtc *crtc);
#define MAX_COLOR_LEGACY_LUT_ENTRIES 256
void amdgpu_dm_init_color_mod(void);
int amdgpu_dm_set_degamma_lut(struct drm_crtc_state *crtc_state,
struct dc_plane_state *dc_plane_state);
void amdgpu_dm_set_ctm(struct dm_crtc_state *crtc);
int amdgpu_dm_set_regamma_lut(struct dm_crtc_state *crtc);
int amdgpu_dm_update_crtc_color_mgmt(struct dm_crtc_state *crtc);
int amdgpu_dm_update_plane_color_mgmt(struct dm_crtc_state *crtc,
struct dc_plane_state *dc_plane_state);
extern const struct drm_encoder_helper_funcs amdgpu_dm_encoder_helper_funcs;

View File

@ -27,6 +27,47 @@
#include "amdgpu_dm.h"
#include "dc.h"
#include "modules/color/color_gamma.h"
#include "basics/conversion.h"
/*
* The DC interface to HW gives us the following color management blocks
* per pipe (surface):
*
* - Input gamma LUT (de-normalized)
* - Input CSC (normalized)
* - Surface degamma LUT (normalized)
* - Surface CSC (normalized)
* - Surface regamma LUT (normalized)
* - Output CSC (normalized)
*
* But these aren't a direct mapping to DRM color properties. The current DRM
* interface exposes CRTC degamma, CRTC CTM and CRTC regamma while our hardware
* is essentially giving:
*
* Plane CTM -> Plane degamma -> Plane CTM -> Plane regamma -> Plane CTM
*
* The input gamma LUT block isn't really applicable here since it operates
* on the actual input data itself rather than the HW fp representation. The
* input and output CSC blocks are technically available to use as part of
* the DC interface but are typically used internally by DC for conversions
* between color spaces. These could be blended together with user
* adjustments in the future but for now these should remain untouched.
*
* The pipe blending also happens after these blocks so we don't actually
* support any CRTC props with correct blending with multiple planes - but we
* can still support CRTC color management properties in DM in most single
* plane cases correctly with clever management of the DC interface in DM.
*
* As per DRM documentation, blocks should be in hardware bypass when their
* respective property is set to NULL. A linear DGM/RGM LUT should also
* considered as putting the respective block into bypass mode.
*
* This means that the following
* configuration is assumed to be the default:
*
* Plane DGM Bypass -> Plane CTM Bypass -> Plane RGM Bypass -> ...
* CRTC DGM Bypass -> CRTC CTM Bypass -> CRTC RGM Bypass
*/
#define MAX_DRM_LUT_VALUE 0xFFFF
@ -41,6 +82,13 @@ void amdgpu_dm_init_color_mod(void)
setup_x_points_distribution();
}
/* Extracts the DRM lut and lut size from a blob. */
static const struct drm_color_lut *
__extract_blob_lut(const struct drm_property_blob *blob, uint32_t *size)
{
*size = blob ? drm_color_lut_size(blob) : 0;
return blob ? (struct drm_color_lut *)blob->data : NULL;
}
/*
* Return true if the given lut is a linear mapping of values, i.e. it acts
@ -50,7 +98,7 @@ void amdgpu_dm_init_color_mod(void)
* f(a) = (0xFF00/MAX_COLOR_LUT_ENTRIES-1)a; for integer a in
* [0, MAX_COLOR_LUT_ENTRIES)
*/
static bool __is_lut_linear(struct drm_color_lut *lut, uint32_t size)
static bool __is_lut_linear(const struct drm_color_lut *lut, uint32_t size)
{
int i;
uint32_t expected;
@ -75,9 +123,8 @@ static bool __is_lut_linear(struct drm_color_lut *lut, uint32_t size)
* Convert the drm_color_lut to dc_gamma. The conversion depends on the size
* of the lut - whether or not it's legacy.
*/
static void __drm_lut_to_dc_gamma(struct drm_color_lut *lut,
struct dc_gamma *gamma,
bool is_legacy)
static void __drm_lut_to_dc_gamma(const struct drm_color_lut *lut,
struct dc_gamma *gamma, bool is_legacy)
{
uint32_t r, g, b;
int i;
@ -107,103 +154,16 @@ static void __drm_lut_to_dc_gamma(struct drm_color_lut *lut,
}
}
/**
* amdgpu_dm_set_regamma_lut: Set regamma lut for the given CRTC.
* @crtc: amdgpu_dm crtc state
*
* Update the underlying dc_stream_state's output transfer function (OTF) in
* preparation for hardware commit. If no lut is specified by user, we default
* to SRGB.
*
* RETURNS:
* 0 on success, -ENOMEM if memory cannot be allocated to calculate the OTF.
/*
* Converts a DRM CTM to a DC CSC float matrix.
* The matrix needs to be a 3x4 (12 entry) matrix.
*/
int amdgpu_dm_set_regamma_lut(struct dm_crtc_state *crtc)
static void __drm_ctm_to_dc_matrix(const struct drm_color_ctm *ctm,
struct fixed31_32 *matrix)
{
struct drm_property_blob *blob = crtc->base.gamma_lut;
struct dc_stream_state *stream = crtc->stream;
struct amdgpu_device *adev = (struct amdgpu_device *)
crtc->base.state->dev->dev_private;
struct drm_color_lut *lut;
uint32_t lut_size;
struct dc_gamma *gamma = NULL;
enum dc_transfer_func_type old_type = stream->out_transfer_func->type;
bool ret;
if (!blob && adev->asic_type <= CHIP_RAVEN) {
/* By default, use the SRGB predefined curve.*/
stream->out_transfer_func->type = TF_TYPE_PREDEFINED;
stream->out_transfer_func->tf = TRANSFER_FUNCTION_SRGB;
return 0;
}
if (blob) {
lut = (struct drm_color_lut *)blob->data;
lut_size = blob->length / sizeof(struct drm_color_lut);
gamma = dc_create_gamma();
if (!gamma)
return -ENOMEM;
gamma->num_entries = lut_size;
if (gamma->num_entries == MAX_COLOR_LEGACY_LUT_ENTRIES)
gamma->type = GAMMA_RGB_256;
else if (gamma->num_entries == MAX_COLOR_LUT_ENTRIES)
gamma->type = GAMMA_CS_TFM_1D;
else {
/* Invalid lut size */
dc_gamma_release(&gamma);
return -EINVAL;
}
/* Convert drm_lut into dc_gamma */
__drm_lut_to_dc_gamma(lut, gamma, gamma->type == GAMMA_RGB_256);
}
/* predefined gamma ROM only exist for RAVEN and pre-RAVEN ASIC,
* set canRomBeUsed accordingly
*/
stream->out_transfer_func->type = TF_TYPE_DISTRIBUTED_POINTS;
ret = mod_color_calculate_regamma_params(stream->out_transfer_func,
gamma, true, adev->asic_type <= CHIP_RAVEN, NULL);
if (gamma)
dc_gamma_release(&gamma);
if (!ret) {
stream->out_transfer_func->type = old_type;
DRM_ERROR("Out of memory when calculating regamma params\n");
return -ENOMEM;
}
return 0;
}
/**
* amdgpu_dm_set_ctm: Set the color transform matrix for the given CRTC.
* @crtc: amdgpu_dm crtc state
*
* Update the underlying dc_stream_state's gamut remap matrix in preparation
* for hardware commit. If no matrix is specified by user, gamut remap will be
* disabled.
*/
void amdgpu_dm_set_ctm(struct dm_crtc_state *crtc)
{
struct drm_property_blob *blob = crtc->base.ctm;
struct dc_stream_state *stream = crtc->stream;
struct drm_color_ctm *ctm;
int64_t val;
int i;
if (!blob) {
stream->gamut_remap_matrix.enable_remap = false;
return;
}
stream->gamut_remap_matrix.enable_remap = true;
ctm = (struct drm_color_ctm *)blob->data;
/*
* DRM gives a 3x3 matrix, but DC wants 3x4. Assuming we're operating
* with homogeneous coordinates, augment the matrix with 0's.
@ -215,83 +175,306 @@ void amdgpu_dm_set_ctm(struct dm_crtc_state *crtc)
for (i = 0; i < 12; i++) {
/* Skip 4th element */
if (i % 4 == 3) {
stream->gamut_remap_matrix.matrix[i] = dc_fixpt_zero;
matrix[i] = dc_fixpt_zero;
continue;
}
/* gamut_remap_matrix[i] = ctm[i - floor(i/4)] */
val = ctm->matrix[i - (i/4)];
val = ctm->matrix[i - (i / 4)];
/* If negative, convert to 2's complement. */
if (val & (1ULL << 63))
val = -(val & ~(1ULL << 63));
stream->gamut_remap_matrix.matrix[i].value = val;
matrix[i].value = val;
}
}
/**
* amdgpu_dm_set_degamma_lut: Set degamma lut for the given CRTC.
* @crtc: amdgpu_dm crtc state
*
* Update the underlying dc_stream_state's input transfer function (ITF) in
* preparation for hardware commit. If no lut is specified by user, we default
* to SRGB degamma.
*
* We support degamma bypass, predefined SRGB, and custom degamma
*
* RETURNS:
* 0 on success
* -EINVAL if crtc_state has a degamma_lut of invalid size
* -ENOMEM if gamma allocation fails
*/
int amdgpu_dm_set_degamma_lut(struct drm_crtc_state *crtc_state,
struct dc_plane_state *dc_plane_state)
/* Calculates the legacy transfer function - only for sRGB input space. */
static int __set_legacy_tf(struct dc_transfer_func *func,
const struct drm_color_lut *lut, uint32_t lut_size,
bool has_rom)
{
struct drm_property_blob *blob = crtc_state->degamma_lut;
struct drm_color_lut *lut;
uint32_t lut_size;
struct dc_gamma *gamma;
bool ret;
struct dc_gamma *gamma = NULL;
bool res;
if (!blob) {
/* Default to SRGB */
dc_plane_state->in_transfer_func->type = TF_TYPE_PREDEFINED;
dc_plane_state->in_transfer_func->tf = TRANSFER_FUNCTION_SRGB;
return 0;
}
lut = (struct drm_color_lut *)blob->data;
if (__is_lut_linear(lut, MAX_COLOR_LUT_ENTRIES)) {
dc_plane_state->in_transfer_func->type = TF_TYPE_BYPASS;
dc_plane_state->in_transfer_func->tf = TRANSFER_FUNCTION_LINEAR;
return 0;
}
ASSERT(lut && lut_size == MAX_COLOR_LEGACY_LUT_ENTRIES);
gamma = dc_create_gamma();
if (!gamma)
return -ENOMEM;
lut_size = blob->length / sizeof(struct drm_color_lut);
gamma->type = GAMMA_RGB_256;
gamma->num_entries = lut_size;
if (gamma->num_entries == MAX_COLOR_LUT_ENTRIES)
__drm_lut_to_dc_gamma(lut, gamma, true);
res = mod_color_calculate_regamma_params(func, gamma, true, has_rom,
NULL);
return res ? 0 : -ENOMEM;
}
/* Calculates the output transfer function based on expected input space. */
static int __set_output_tf(struct dc_transfer_func *func,
const struct drm_color_lut *lut, uint32_t lut_size,
bool has_rom)
{
struct dc_gamma *gamma = NULL;
bool res;
ASSERT(lut && lut_size == MAX_COLOR_LUT_ENTRIES);
gamma = dc_create_gamma();
if (!gamma)
return -ENOMEM;
gamma->num_entries = lut_size;
__drm_lut_to_dc_gamma(lut, gamma, false);
if (func->tf == TRANSFER_FUNCTION_LINEAR) {
/*
* Color module doesn't like calculating regamma params
* on top of a linear input. But degamma params can be used
* instead to simulate this.
*/
gamma->type = GAMMA_CUSTOM;
else {
dc_gamma_release(&gamma);
return -EINVAL;
res = mod_color_calculate_degamma_params(func, gamma, true);
} else {
/*
* Assume sRGB. The actual mapping will depend on whether the
* input was legacy or not.
*/
gamma->type = GAMMA_CS_TFM_1D;
res = mod_color_calculate_regamma_params(func, gamma, false,
has_rom, NULL);
}
dc_gamma_release(&gamma);
return res ? 0 : -ENOMEM;
}
/* Caculates the input transfer function based on expected input space. */
static int __set_input_tf(struct dc_transfer_func *func,
const struct drm_color_lut *lut, uint32_t lut_size)
{
struct dc_gamma *gamma = NULL;
bool res;
gamma = dc_create_gamma();
if (!gamma)
return -ENOMEM;
gamma->type = GAMMA_CUSTOM;
gamma->num_entries = lut_size;
__drm_lut_to_dc_gamma(lut, gamma, false);
dc_plane_state->in_transfer_func->type = TF_TYPE_DISTRIBUTED_POINTS;
ret = mod_color_calculate_degamma_params(dc_plane_state->in_transfer_func, gamma, true);
res = mod_color_calculate_degamma_params(func, gamma, true);
dc_gamma_release(&gamma);
if (!ret) {
dc_plane_state->in_transfer_func->type = TF_TYPE_BYPASS;
DRM_ERROR("Out of memory when calculating degamma params\n");
return -ENOMEM;
return res ? 0 : -ENOMEM;
}
/**
* amdgpu_dm_update_crtc_color_mgmt: Maps DRM color management to DC stream.
* @crtc: amdgpu_dm crtc state
*
* With no plane level color management properties we're free to use any
* of the HW blocks as long as the CRTC CTM always comes before the
* CRTC RGM and after the CRTC DGM.
*
* The CRTC RGM block will be placed in the RGM LUT block if it is non-linear.
* The CRTC DGM block will be placed in the DGM LUT block if it is non-linear.
* The CRTC CTM will be placed in the gamut remap block if it is non-linear.
*
* The RGM block is typically more fully featured and accurate across
* all ASICs - DCE can't support a custom non-linear CRTC DGM.
*
* For supporting both plane level color management and CRTC level color
* management at once we have to either restrict the usage of CRTC properties
* or blend adjustments together.
*
* Returns 0 on success.
*/
int amdgpu_dm_update_crtc_color_mgmt(struct dm_crtc_state *crtc)
{
struct dc_stream_state *stream = crtc->stream;
struct amdgpu_device *adev =
(struct amdgpu_device *)crtc->base.state->dev->dev_private;
bool has_rom = adev->asic_type <= CHIP_RAVEN;
struct drm_color_ctm *ctm = NULL;
const struct drm_color_lut *degamma_lut, *regamma_lut;
uint32_t degamma_size, regamma_size;
bool has_regamma, has_degamma;
bool is_legacy;
int r;
degamma_lut = __extract_blob_lut(crtc->base.degamma_lut, &degamma_size);
if (degamma_lut && degamma_size != MAX_COLOR_LUT_ENTRIES)
return -EINVAL;
regamma_lut = __extract_blob_lut(crtc->base.gamma_lut, &regamma_size);
if (regamma_lut && regamma_size != MAX_COLOR_LUT_ENTRIES &&
regamma_size != MAX_COLOR_LEGACY_LUT_ENTRIES)
return -EINVAL;
has_degamma =
degamma_lut && !__is_lut_linear(degamma_lut, degamma_size);
has_regamma =
regamma_lut && !__is_lut_linear(regamma_lut, regamma_size);
is_legacy = regamma_size == MAX_COLOR_LEGACY_LUT_ENTRIES;
/* Reset all adjustments. */
crtc->cm_has_degamma = false;
crtc->cm_is_degamma_srgb = false;
/* Setup regamma and degamma. */
if (is_legacy) {
/*
* Legacy regamma forces us to use the sRGB RGM as a base.
* This also means we can't use linear DGM since DGM needs
* to use sRGB as a base as well, resulting in incorrect CRTC
* DGM and CRTC CTM.
*
* TODO: Just map this to the standard regamma interface
* instead since this isn't really right. One of the cases
* where this setup currently fails is trying to do an
* inverse color ramp in legacy userspace.
*/
crtc->cm_is_degamma_srgb = true;
stream->out_transfer_func->type = TF_TYPE_DISTRIBUTED_POINTS;
stream->out_transfer_func->tf = TRANSFER_FUNCTION_SRGB;
r = __set_legacy_tf(stream->out_transfer_func, regamma_lut,
regamma_size, has_rom);
if (r)
return r;
} else if (has_regamma) {
/* CRTC RGM goes into RGM LUT. */
stream->out_transfer_func->type = TF_TYPE_DISTRIBUTED_POINTS;
stream->out_transfer_func->tf = TRANSFER_FUNCTION_LINEAR;
r = __set_output_tf(stream->out_transfer_func, regamma_lut,
regamma_size, has_rom);
if (r)
return r;
} else {
/*
* No CRTC RGM means we can just put the block into bypass
* since we don't have any plane level adjustments using it.
*/
stream->out_transfer_func->type = TF_TYPE_BYPASS;
stream->out_transfer_func->tf = TRANSFER_FUNCTION_LINEAR;
}
/*
* CRTC DGM goes into DGM LUT. It would be nice to place it
* into the RGM since it's a more featured block but we'd
* have to place the CTM in the OCSC in that case.
*/
crtc->cm_has_degamma = has_degamma;
/* Setup CRTC CTM. */
if (crtc->base.ctm) {
ctm = (struct drm_color_ctm *)crtc->base.ctm->data;
/*
* Gamut remapping must be used for gamma correction
* since it comes before the regamma correction.
*
* OCSC could be used for gamma correction, but we'd need to
* blend the adjustments together with the required output
* conversion matrix - so just use the gamut remap block
* for now.
*/
__drm_ctm_to_dc_matrix(ctm, stream->gamut_remap_matrix.matrix);
stream->gamut_remap_matrix.enable_remap = true;
stream->csc_color_matrix.enable_adjustment = false;
} else {
/* Bypass CTM. */
stream->gamut_remap_matrix.enable_remap = false;
stream->csc_color_matrix.enable_adjustment = false;
}
return 0;
}
/**
* amdgpu_dm_update_plane_color_mgmt: Maps DRM color management to DC plane.
* @crtc: amdgpu_dm crtc state
* @ dc_plane_state: target DC surface
*
* Update the underlying dc_stream_state's input transfer function (ITF) in
* preparation for hardware commit. The transfer function used depends on
* the prepartion done on the stream for color management.
*
* Returns 0 on success.
*/
int amdgpu_dm_update_plane_color_mgmt(struct dm_crtc_state *crtc,
struct dc_plane_state *dc_plane_state)
{
const struct drm_color_lut *degamma_lut;
uint32_t degamma_size;
int r;
if (crtc->cm_has_degamma) {
degamma_lut = __extract_blob_lut(crtc->base.degamma_lut,
&degamma_size);
ASSERT(degamma_size == MAX_COLOR_LUT_ENTRIES);
dc_plane_state->in_transfer_func->type =
TF_TYPE_DISTRIBUTED_POINTS;
/*
* This case isn't fully correct, but also fairly
* uncommon. This is userspace trying to use a
* legacy gamma LUT + atomic degamma LUT
* at the same time.
*
* Legacy gamma requires the input to be in linear
* space, so that means we need to apply an sRGB
* degamma. But color module also doesn't support
* a user ramp in this case so the degamma will
* be lost.
*
* Even if we did support it, it's still not right:
*
* Input -> CRTC DGM -> sRGB DGM -> CRTC CTM ->
* sRGB RGM -> CRTC RGM -> Output
*
* The CSC will be done in the wrong space since
* we're applying an sRGB DGM on top of the CRTC
* DGM.
*
* TODO: Don't use the legacy gamma interface and just
* map these to the atomic one instead.
*/
if (crtc->cm_is_degamma_srgb)
dc_plane_state->in_transfer_func->tf =
TRANSFER_FUNCTION_SRGB;
else
dc_plane_state->in_transfer_func->tf =
TRANSFER_FUNCTION_LINEAR;
r = __set_input_tf(dc_plane_state->in_transfer_func,
degamma_lut, degamma_size);
if (r)
return r;
} else if (crtc->cm_is_degamma_srgb) {
/*
* For legacy gamma support we need the regamma input
* in linear space. Assume that the input is sRGB.
*/
dc_plane_state->in_transfer_func->type = TF_TYPE_PREDEFINED;
dc_plane_state->in_transfer_func->tf = TRANSFER_FUNCTION_SRGB;
} else {
/* ...Otherwise we can just bypass the DGM block. */
dc_plane_state->in_transfer_func->type = TF_TYPE_BYPASS;
dc_plane_state->in_transfer_func->tf = TRANSFER_FUNCTION_LINEAR;
}
return 0;
}