Brought up in a discussion for enabling gamma on fsl-dcu. Cc: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> Cc: Meng Yi <meng.yi@xxxxxxx> Cc: Lionel Landwerlin <lionel.g.landwerlin@xxxxxxxxx> Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxxx> --- drivers/gpu/drm/drm_color_mgmt.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/drivers/gpu/drm/drm_color_mgmt.c b/drivers/gpu/drm/drm_color_mgmt.c index d28ffdd2b929..6543ebde501a 100644 --- a/drivers/gpu/drm/drm_color_mgmt.c +++ b/drivers/gpu/drm/drm_color_mgmt.c @@ -41,6 +41,10 @@ * nor use all the elements of the LUT (for example the hardware might * choose to interpolate between LUT[0] and LUT[4]). * + * Setting this to NULL (blob property value set to 0) means a + * linear/pass-thru gamma table should be used. This is generally the + * driver boot-up state too. + * * “DEGAMMA_LUT_SIZE”: * Unsinged range property to give the size of the lookup table to be set * on the DEGAMMA_LUT property (the size depends on the underlying @@ -54,6 +58,10 @@ * lookup through the gamma LUT. The data is interpreted as a struct * &drm_color_ctm. * + * Setting this to NULL (blob property value set to 0) means a + * unit/pass-thru matrix should be used. This is generally the driver + * boot-up state too. + * * “GAMMA_LUT”: * Blob property to set the gamma lookup table (LUT) mapping pixel data * after the transformation matrix to data sent to the connector. The @@ -62,6 +70,10 @@ * nor use all the elements of the LUT (for example the hardware might * choose to interpolate between LUT[0] and LUT[4]). * + * Setting this to NULL (blob property value set to 0) means a + * linear/pass-thru gamma table should be used. This is generally the + * driver boot-up state too. + * * “GAMMA_LUT_SIZE”: * Unsigned range property to give the size of the lookup table to be set * on the GAMMA_LUT property (the size depends on the underlying hardware). -- 2.9.3 _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
