From: Andres Calderon Jaramillo <andrescj@xxxxxxxxxxxx> Prevent the ICL HDR plane pipeline from performing YUV color range correction twice when the input is in limited range. This is done by removing the limited-range code from icl_program_input_csc(). Before this patch the following could happen: user space gives us a YUV buffer in limited range; per the pipeline in [1], the plane would first go through a "YUV Range correct" stage that expands the range; the plane would then go through the "Input CSC" stage which would also expand the range because icl_program_input_csc() would use a matrix and an offset that assume limited-range input; this would ultimately cause dark and light colors to appear darker and lighter than they should respectively. This is an issue because if a buffer switches between being scanned out and being composited with the GPU, the user will see a color difference. If this switching happens quickly and frequently, the user will perceive this as a flickering. [1] https://01.org/sites/default/files/documentation/intel-gfx-prm-osrc-icllp-vol12-displayengine_0.pdf#page=281 Signed-off-by: Andres Calderon Jaramillo <andrescj@xxxxxxxxxxxx> --- Changelog since v1: - Don't skip the YUV range correction stage. Instead, use that stage and modify icl_program_input_csc() to always assume full-range input. drivers/gpu/drm/i915/display/intel_display.c | 2 + drivers/gpu/drm/i915/display/intel_sprite.c | 65 +++----------------- 2 files changed, 12 insertions(+), 55 deletions(-) diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c index 761be8deaa9b..8fb9b4f8c1df 100644 --- a/drivers/gpu/drm/i915/display/intel_display.c +++ b/drivers/gpu/drm/i915/display/intel_display.c @@ -4811,6 +4811,8 @@ u32 glk_plane_color_ctl(const struct intel_crtc_state *crtc_state, plane_color_ctl |= PLANE_COLOR_YUV_RANGE_CORRECTION_DISABLE; } else if (fb->format->is_yuv) { plane_color_ctl |= PLANE_COLOR_INPUT_CSC_ENABLE; + if (plane_state->hw.color_range == DRM_COLOR_YCBCR_FULL_RANGE) + plane_color_ctl |= PLANE_COLOR_YUV_RANGE_CORRECTION_DISABLE; } return plane_color_ctl; diff --git a/drivers/gpu/drm/i915/display/intel_sprite.c b/drivers/gpu/drm/i915/display/intel_sprite.c index b7e208816074..121e1b5120fd 100644 --- a/drivers/gpu/drm/i915/display/intel_sprite.c +++ b/drivers/gpu/drm/i915/display/intel_sprite.c @@ -633,13 +633,19 @@ skl_program_scaler(struct intel_plane *plane, /* Preoffset values for YUV to RGB Conversion */ #define PREOFF_YUV_TO_RGB_HI 0x1800 -#define PREOFF_YUV_TO_RGB_ME 0x1F00 +#define PREOFF_YUV_TO_RGB_ME 0x0000 #define PREOFF_YUV_TO_RGB_LO 0x1800 #define ROFF(x) (((x) & 0xffff) << 16) #define GOFF(x) (((x) & 0xffff) << 0) #define BOFF(x) (((x) & 0xffff) << 16) +/* + * Programs the input color space conversion stage for ICL HDR planes. + * Note that it is assumed that this stage always happens after YUV + * range correction. Thus, the input to this stage is assumed to be + * in full-range YCbCr. + */ static void icl_program_input_csc(struct intel_plane *plane, const struct intel_crtc_state *crtc_state, @@ -687,52 +693,7 @@ icl_program_input_csc(struct intel_plane *plane, 0x0, 0x7800, 0x7F10, }, }; - - /* Matrix for Limited Range to Full Range Conversion */ - static const u16 input_csc_matrix_lr[][9] = { - /* - * BT.601 Limted range YCbCr -> full range RGB - * The matrix required is : - * [1.164384, 0.000, 1.596027, - * 1.164384, -0.39175, -0.812813, - * 1.164384, 2.017232, 0.0000] - */ - [DRM_COLOR_YCBCR_BT601] = { - 0x7CC8, 0x7950, 0x0, - 0x8D00, 0x7950, 0x9C88, - 0x0, 0x7950, 0x6810, - }, - /* - * BT.709 Limited range YCbCr -> full range RGB - * The matrix required is : - * [1.164384, 0.000, 1.792741, - * 1.164384, -0.213249, -0.532909, - * 1.164384, 2.112402, 0.0000] - */ - [DRM_COLOR_YCBCR_BT709] = { - 0x7E58, 0x7950, 0x0, - 0x8888, 0x7950, 0xADA8, - 0x0, 0x7950, 0x6870, - }, - /* - * BT.2020 Limited range YCbCr -> full range RGB - * The matrix required is : - * [1.164, 0.000, 1.678, - * 1.164, -0.1873, -0.6504, - * 1.164, 2.1417, 0.0000] - */ - [DRM_COLOR_YCBCR_BT2020] = { - 0x7D70, 0x7950, 0x0, - 0x8A68, 0x7950, 0xAC00, - 0x0, 0x7950, 0x6890, - }, - }; - const u16 *csc; - - if (plane_state->hw.color_range == DRM_COLOR_YCBCR_FULL_RANGE) - csc = input_csc_matrix[plane_state->hw.color_encoding]; - else - csc = input_csc_matrix_lr[plane_state->hw.color_encoding]; + const u16 *csc = input_csc_matrix[plane_state->hw.color_encoding]; intel_de_write_fw(dev_priv, PLANE_INPUT_CSC_COEFF(pipe, plane_id, 0), ROFF(csc[0]) | GOFF(csc[1])); @@ -749,14 +710,8 @@ icl_program_input_csc(struct intel_plane *plane, intel_de_write_fw(dev_priv, PLANE_INPUT_CSC_PREOFF(pipe, plane_id, 0), PREOFF_YUV_TO_RGB_HI); - if (plane_state->hw.color_range == DRM_COLOR_YCBCR_FULL_RANGE) - intel_de_write_fw(dev_priv, - PLANE_INPUT_CSC_PREOFF(pipe, plane_id, 1), - 0); - else - intel_de_write_fw(dev_priv, - PLANE_INPUT_CSC_PREOFF(pipe, plane_id, 1), - PREOFF_YUV_TO_RGB_ME); + intel_de_write_fw(dev_priv, PLANE_INPUT_CSC_PREOFF(pipe, plane_id, 1), + PREOFF_YUV_TO_RGB_ME); intel_de_write_fw(dev_priv, PLANE_INPUT_CSC_PREOFF(pipe, plane_id, 2), PREOFF_YUV_TO_RGB_LO); intel_de_write_fw(dev_priv, -- 2.29.2.684.gfbc64c5ab5-goog _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
