1 From 6c276e5d2c0ee362e4b860845401e095773fad7f Mon Sep 17 00:00:00 2001
2 From: Dave Stevenson <dave.stevenson@raspberrypi.com>
3 Date: Thu, 13 Jan 2022 11:30:42 +0000
4 Subject: [PATCH] drm/vc4: Disable Gamma control on HVS5 due to issues
7 Still under investigation, but the conditions under which the HVS
8 will accept values written to the gamma PWL are not straightforward.
10 Disable gamma on HVS5 again until it can be resolved to avoid
11 gamma being enabled with an incorrect table.
13 Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
15 drivers/gpu/drm/vc4/vc4_crtc.c | 8 +-------
16 1 file changed, 1 insertion(+), 7 deletions(-)
18 --- a/drivers/gpu/drm/vc4/vc4_crtc.c
19 +++ b/drivers/gpu/drm/vc4/vc4_crtc.c
20 @@ -1182,15 +1182,9 @@ int vc4_crtc_init(struct drm_device *drm
22 if (!vc4->hvs->hvs5) {
23 drm_mode_crtc_set_gamma_size(crtc, ARRAY_SIZE(vc4_crtc->lut_r));
25 - /* This is a lie for hvs5 which uses a 16 point PWL, but it
26 - * allows for something smarter than just 16 linearly spaced
27 - * segments. Conversion is done in vc5_hvs_update_gamma_lut.
29 - drm_mode_crtc_set_gamma_size(crtc, 256);
30 + drm_crtc_enable_color_mgmt(crtc, 0, false, crtc->gamma_size);
33 - drm_crtc_enable_color_mgmt(crtc, 0, false, crtc->gamma_size);
35 if (!vc4->hvs->hvs5) {
36 /* We support CTM, but only for one CRTC at a time. It's therefore