diff options
Diffstat (limited to 'drivers/gpu/drm/i915/display/intel_color.c')
| -rw-r--r-- | drivers/gpu/drm/i915/display/intel_color.c | 27 |
1 files changed, 26 insertions, 1 deletions
diff --git a/drivers/gpu/drm/i915/display/intel_color.c b/drivers/gpu/drm/i915/display/intel_color.c index 8966e6560516..454607b4a02a 100644 --- a/drivers/gpu/drm/i915/display/intel_color.c +++ b/drivers/gpu/drm/i915/display/intel_color.c @@ -1453,6 +1453,16 @@ static int glk_degamma_lut_size(struct drm_i915_private *i915) return 35; } +/* + * change_lut_val_precision: helper function to upscale or downscale lut values. + * Parameters 'to' and 'from' needs to be less than 32. This should be sufficient + * as currently there are no lut values exceeding 32 bit. + */ +static u32 change_lut_val_precision(u32 lut_val, int to, int from) +{ + return mul_u32_u32(lut_val, (1 << to)) / (1 << from); +} + static void glk_load_degamma_lut(const struct intel_crtc_state *crtc_state, const struct drm_property_blob *blob) { @@ -1487,8 +1497,15 @@ static void glk_load_degamma_lut(const struct intel_crtc_state *crtc_state, * ToDo: Extend to max 7.0. Enable 32 bit input value * as compared to just 16 to achieve this. */ + u32 lut_val; + + if (DISPLAY_VER(i915) >= 14) + lut_val = change_lut_val_precision(lut[i].green, 24, 16); + else + lut_val = lut[i].green; + ilk_lut_write(crtc_state, PRE_CSC_GAMC_DATA(pipe), - lut[i].green); + lut_val); } /* Clamp values > 1.0. */ @@ -3439,6 +3456,14 @@ static struct drm_property_blob *glk_read_degamma_lut(struct intel_crtc *crtc) for (i = 0; i < lut_size; i++) { u32 val = intel_de_read_fw(dev_priv, PRE_CSC_GAMC_DATA(pipe)); + /* + * For MTL and beyond, convert back the 24 bit lut values + * read from HW to 16 bit values to maintain parity with + * userspace values + */ + if (DISPLAY_VER(dev_priv) >= 14) + val = change_lut_val_precision(val, 16, 24); + lut[i].red = val; lut[i].green = val; lut[i].blue = val; |