From 4c04b5181a67eac2b98e5837e2489756ab79e59c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jouni=20H=C3=B6gander?= <jouni.hogander@intel.com>
Date: Wed, 13 Apr 2022 11:28:26 +0300
Subject: drm/i915: Check EDID for HDR static metadata when choosing blc
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Git-commit: c05d8332f5d23fa3b521911cbe55a2b67fb21248
Patch-mainline: v5.18-rc5
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
We have now seen panel (XMG Core 15 e21 laptop) advertizing support
for Intel proprietary eDP backlight control via DPCD registers, but
actually working only with legacy pwm control.
This patch adds panel EDID check for possible HDR static metadata and
Intel proprietary eDP backlight control is used only if that exists.
Missing HDR static metadata is ignored if user specifically asks for
Intel proprietary eDP backlight control via enable_dpcd_backlight
parameter.
v2 :
- Ignore missing HDR static metadata if Intel proprietary eDP
backlight control is forced via i915.enable_dpcd_backlight
- Printout info message if panel is missing HDR static metadata and
support for Intel proprietary eDP backlight control is detected
Fixes: 4a8d79901d5b ("drm/i915/dp: Enable Intel's HDR backlight interface (only SDR for now)")
Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/5284
Cc: Lyude Paul <lyude@redhat.com>
Cc: Mika Kahola <mika.kahola@intel.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Filippo Falezza <filippo.falezza@outlook.it>
Cc: stable@vger.kernel.org
Signed-off-by: Jouni Högander <jouni.hogander@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220413082826.120634-1-jouni.hogander@intel.com
Reviewed-by: Lyude Paul <lyude@redhat.com>
(cherry picked from commit b4b157577cb1de13bee8bebc3576f1de6799a921)
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
.../drm/i915/display/intel_dp_aux_backlight.c | 34 ++++++++++++++-----
1 file changed, 26 insertions(+), 8 deletions(-)
diff --git a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
index 97cf3cac0105..fb6cf30ee628 100644
--- a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
@@ -97,6 +97,14 @@
#define INTEL_EDP_BRIGHTNESS_OPTIMIZATION_1 0x359
+enum intel_dp_aux_backlight_modparam {
+ INTEL_DP_AUX_BACKLIGHT_AUTO = -1,
+ INTEL_DP_AUX_BACKLIGHT_OFF = 0,
+ INTEL_DP_AUX_BACKLIGHT_ON = 1,
+ INTEL_DP_AUX_BACKLIGHT_FORCE_VESA = 2,
+ INTEL_DP_AUX_BACKLIGHT_FORCE_INTEL = 3,
+};
+
/* Intel EDP backlight callbacks */
static bool
intel_dp_aux_supports_hdr_backlight(struct intel_connector *connector)
@@ -126,6 +134,24 @@ intel_dp_aux_supports_hdr_backlight(struct intel_connector *connector)
return false;
}
+ /*
+ * If we don't have HDR static metadata there is no way to
+ * runtime detect used range for nits based control. For now
+ * do not use Intel proprietary eDP backlight control if we
+ * don't have this data in panel EDID. In case we find panel
+ * which supports only nits based control, but doesn't provide
+ * HDR static metadata we need to start maintaining table of
+ * ranges for such panels.
+ */
+ if (i915->params.enable_dpcd_backlight != INTEL_DP_AUX_BACKLIGHT_FORCE_INTEL &&
+ !(connector->base.hdr_sink_metadata.hdmi_type1.metadata_type &
+ BIT(HDMI_STATIC_METADATA_TYPE1))) {
+ drm_info(&i915->drm,
+ "Panel is missing HDR static metadata. Possible support for Intel HDR backlight interface is not used. If your backlight controls don't work try booting with i915.enable_dpcd_backlight=%d. needs this, please file a _new_ bug report on drm/i915, see " FDO_BUG_URL " for details.\n",
+ INTEL_DP_AUX_BACKLIGHT_FORCE_INTEL);
+ return false;
+ }
+
panel->backlight.edp.intel.sdr_uses_aux =
tcon_cap[2] & INTEL_EDP_SDR_TCON_BRIGHTNESS_AUX_CAP;
@@ -413,14 +439,6 @@ static const struct intel_panel_bl_funcs intel_dp_vesa_bl_funcs = {
.get = intel_dp_aux_vesa_get_backlight,
};
-enum intel_dp_aux_backlight_modparam {
- INTEL_DP_AUX_BACKLIGHT_AUTO = -1,
- INTEL_DP_AUX_BACKLIGHT_OFF = 0,
- INTEL_DP_AUX_BACKLIGHT_ON = 1,
- INTEL_DP_AUX_BACKLIGHT_FORCE_VESA = 2,
- INTEL_DP_AUX_BACKLIGHT_FORCE_INTEL = 3,
-};
-
int intel_dp_aux_init_backlight_funcs(struct intel_connector *connector)
{
struct drm_device *dev = connector->base.dev;
--
2.38.1