From: Andres Calderon Jaramillo andrescj@chromium.org
commit 00f9a08fbc3c703b71842a5425c1eb82053c8a70 upstream.
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-vo...
Cc: stable@vger.kernel.org Signed-off-by: Andres Calderon Jaramillo andrescj@chromium.org Signed-off-by: Ville Syrjälä ville.syrjala@linux.intel.com Link: https://patchwork.freedesktop.org/patch/msgid/20201215224219.3896256-1-andre... (cherry picked from commit fed387572040e84ead53852a7820e30a30e515d0) Signed-off-by: Jani Nikula jani.nikula@intel.com Link: https://patchwork.freedesktop.org/patch/msgid/20210202084553.30691-1-ville.s... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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(-)
--- a/drivers/gpu/drm/i915/display/intel_display.c +++ b/drivers/gpu/drm/i915/display/intel_display.c @@ -4880,6 +4880,8 @@ u32 glk_plane_color_ctl(const struct int 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; --- a/drivers/gpu/drm/i915/display/intel_sprite.c +++ b/drivers/gpu/drm/i915/display/intel_sprite.c @@ -469,13 +469,19 @@ skl_program_scaler(struct intel_plane *p
/* 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, @@ -523,52 +529,7 @@ icl_program_input_csc(struct intel_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])); @@ -585,14 +546,8 @@ icl_program_input_csc(struct intel_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,