[Intel-gfx] [PATCH v3 2/5] drm/nouveau/kms/nv50-: Explicitly check DPCD backlights for aux enable/brightness

Lyude Paul
2021-10-06T02:41:45Z

Since we don't support hybrid AUX/PWM backlights in nouveau right now,
let's add some explicit checks so that we don't break nouveau once we
enable support for these backlights in other drivers.

Signed-off-by: Lyude Paul <lyude@redhat.com>
---
drivers/gpu/drm/nouveau/nouveau_backlight.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/nouveau/nouveau_backlight.c b/drivers/gpu/drm/nouveau/nouveau_backlight.c
index 1cbd71abc80a..ae2f2abc8f5a 100644
--- a/drivers/gpu/drm/nouveau/nouveau_backlight.c
+++ b/drivers/gpu/drm/nouveau/nouveau_backlight.c
@@ -308,7 +308,10 @@ nv50_backlight_init(struct nouveau_backlight *bl,
if (ret < 0)
return ret;

- if (drm_edp_backlight_supported(edp_dpcd)) {
+ /* TODO: Add support for hybrid PWM/DPCD panels */
+ if (drm_edp_backlight_supported(edp_dpcd) &&
+ (edp_dpcd[1] & DP_EDP_BACKLIGHT_AUX_ENABLE_CAP) &&
+ (edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_AUX_SET_CAP)) {
NV_DEBUG(drm, "DPCD backlight controls supported on %s\n",
nv_conn->base.name);

--
2.31.1