From f1f5daf7839cf5565e8e40f77bd40563e1ef62c7 Mon Sep 17 00:00:00 2001
From: Lyude Paul <lyude@redhat.com>
Date: Fri, 5 Nov 2021 14:33:39 -0400
Subject: drm/nouveau/kms/nv50-: Explicitly check DPCD backlights for aux
enable/brightness
Git-commit: f5dee1283f6289342e720446ac777ce3aaf95f13
Patch-mainline: v5.17-rc1
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225
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.
Reviewed-by: Karol Herbst <kherbst@redhat.com>
Signed-off-by: Lyude Paul <lyude@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211105183342.130810-3-lyude@redhat.com
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
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);
--
2.38.1