Re: [PATCH 21/22] drm/i915: BDW: Pipe level degamma correction

Hi Shashank,

On 9 October 2015 at 20:29, Shashank Sharma shashank.sharma@intel.com wrote:

BDW/SKL/BXT supports Degamma color correction feature, which linearizes the non-linearity due to gamma encoded color values. This will be applied before Color Transformation.

This patch does the following:

1. Adds the core function to program DeGamma correction values for BDW/SKL/BXT platform
2. Adds DeGamma correction macros/defines

Signed-off-by: Shashank Sharma shashank.sharma@intel.com Signed-off-by: Kausal Malladi kausalmalladi@gmail.com

---

drivers/gpu/drm/i915/intel_color_manager.c | 59 ++++++++++++++++++++++++++++++ 1 file changed, 59 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_color_manager.c b/drivers/gpu/drm/i915/intel_color_manager.c index 74f8fc3..e659382 100644 --- a/drivers/gpu/drm/i915/intel_color_manager.c +++ b/drivers/gpu/drm/i915/intel_color_manager.c @@ -273,6 +273,63 @@ static int bdw_set_gamma(struct drm_device *dev, struct drm_property_blob *blob, return 0; }

+static int bdw_set_degamma(struct drm_device *dev,

•   struct drm_property_blob *blob, struct drm_crtc *crtc)
  

+{

•   enum pipe pipe;
  

•   int num_samples, length;
  

•   u32 index, mode;
  

•   u32 pal_prec_index, pal_prec_data;
  

•   struct drm_palette *degamma_data;
  

•   struct drm_crtc_state *state = crtc->state;
  

•   struct drm_i915_private *dev_priv = dev->dev_private;
  

•   struct drm_r32g32b32 *correction_values = NULL;
  

•   if (WARN_ON(!blob))
  

•           return -EINVAL;
  

•   degamma_data = (struct drm_palette *)blob->data;
  

•   pipe = to_intel_crtc(crtc)->pipe;
  

•   num_samples = degamma_data->num_samples;
  

•   if (num_samples == GAMMA_DISABLE_VALS) {
  

•           /* Disable degamma on Pipe */
  

•           mode = I915_READ(GAMMA_MODE(pipe)) & ~GAMMA_MODE_MODE_MASK;
  

•           I915_WRITE(GAMMA_MODE(pipe), mode | GAMMA_MODE_MODE_8BIT);
  

•           state->palette_before_ctm_blob = NULL;
  

•           DRM_DEBUG_DRIVER("Disabling degamma on Pipe %c\n",
  

•           pipe_name(pipe));
  

•           return 0;
  

•   }
  

•   if (num_samples != BDW_SPLITGAMMA_MAX_VALS) {
  

•           DRM_ERROR("Invalid number of samples\n");
  

•           return -EINVAL;
  

•   }
  

Why don't you use switch statement here ?

•   length = num_samples * sizeof(struct drm_r32g32b32);
  

•   mode = I915_READ(GAMMA_MODE(pipe));
  

•   pal_prec_index = _PREC_PAL_INDEX(pipe);
  

•   pal_prec_data = _PREC_PAL_DATA(pipe);
  

•   correction_values = (struct drm_r32g32b32 *)&degamma_data->lut;
  

•   index = I915_READ(pal_prec_index);
  

•   index |= BDW_INDEX_AUTO_INCREMENT | BDW_INDEX_SPLIT_MODE;
  

•   I915_WRITE(pal_prec_index, index);
  

•   bdw_write_10bit_gamma_precision(dev, correction_values,
  

•           pal_prec_data, BDW_SPLITGAMMA_MAX_VALS);
  

•   /* Enable DeGamma on Pipe */
  

•   mode &= ~GAMMA_MODE_MODE_MASK;
  

•   I915_WRITE(GAMMA_MODE(pipe), mode | GAMMA_MODE_MODE_SPLIT);
  

•   DRM_DEBUG_DRIVER("DeGamma correction enabled on Pipe %c\n",
  

•   pipe_name(pipe));
  

Indentation seems funny here.

Regards, Emil