drm/amd/display: Don't program bypass on linear regamma LUT

Even though this is required for degamma since DCE HW only supports a
couple predefined LUTs we can just program the LUT directly for regamma.

This fixes dark screens which occurs when we program regamma to bypass
while degamma is using srgb LUT.

Signed-off-by: Harry Wentland <harry.wentland@amd.com>
Reviewed-by: Leo Li <sunpeng.li@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_color.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_color.c
index ef5fad8c5aac6904a0fc073e172ebd265d4c80e7..e3d90e918d1b2ad3f37f8d53daf1663b8ee22527 100644 (file)
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_color.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_color.c
@@ -139,13 +139,6 @@ int amdgpu_dm_set_regamma_lut(struct dm_crtc_state *crtc)
        lut = (struct drm_color_lut *)blob->data;
        lut_size = blob->length / sizeof(struct drm_color_lut);
 
-       if (__is_lut_linear(lut, lut_size)) {
-               /* Set to bypass if lut is set to linear */
-               stream->out_transfer_func->type = TF_TYPE_BYPASS;
-               stream->out_transfer_func->tf = TRANSFER_FUNCTION_LINEAR;
-               return 0;
-       }
-
        gamma = dc_create_gamma();
        if (!gamma)
                return -ENOMEM;