At init and if the gamma_lut property is ever removed, the clut registers must be programmed with a default gamma ramp instead of being left in some unknown state.
Fixes: 364a7bf574eb ("drm: atmel-hlcdc: add support for 8-bit color lookup table mode") Signed-off-by: Peter Rosin peda@axentia.se --- drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_plane.c | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_plane.c b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_plane.c index b5bd9b0..0ccd93c 100644 --- a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_plane.c +++ b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_plane.c @@ -429,6 +429,14 @@ static void atmel_hlcdc_plane_update_format(struct atmel_hlcdc_plane *plane, ATMEL_HLCDC_LAYER_FORMAT_CFG, cfg); }
+static void atmel_hlcdc_default_gamma_ramp(struct atmel_hlcdc_layer *layer) +{ + int idx; + + for (idx = 0; idx < ATMEL_HLCDC_CLUT_SIZE; idx++) + atmel_hlcdc_layer_write_clut(layer, idx, idx * 0x10101); +} + static void atmel_hlcdc_plane_update_clut(struct atmel_hlcdc_plane *plane) { struct drm_crtc *crtc = plane->base.crtc; @@ -438,9 +446,14 @@ static void atmel_hlcdc_plane_update_clut(struct atmel_hlcdc_plane *plane) if (!crtc || !crtc->state) return;
- if (!crtc->state->color_mgmt_changed || !crtc->state->gamma_lut) + if (!crtc->state->color_mgmt_changed) return;
+ if (!crtc->state->gamma_lut) { + atmel_hlcdc_default_gamma_ramp(&plane->layer); + return; + } + lut = (struct drm_color_lut *)crtc->state->gamma_lut->data;
for (idx = 0; idx < ATMEL_HLCDC_CLUT_SIZE; idx++, lut++) { @@ -918,6 +931,8 @@ static int atmel_hlcdc_plane_init_properties(struct atmel_hlcdc_plane *plane, 0x40040890); }
+ atmel_hlcdc_default_gamma_ramp(&plane->layer); + return 0; }