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* [PATCH] drm/i915/backlight: Remove try_vesa_interface
@ 2026-02-24  3:13 Suraj Kandpal
  2026-02-24  3:20 ` ✓ CI.KUnit: success for " Patchwork
                   ` (3 more replies)
  0 siblings, 4 replies; 10+ messages in thread
From: Suraj Kandpal @ 2026-02-24  3:13 UTC (permalink / raw)
  To: intel-xe, intel-gfx; +Cc: ankit.k.nautiyal, Suraj Kandpal

Remove try_vesa_interface. This is because we now make VESA Interface
as a fallback mechanism for Panels which needs VESA DPCD AUX backlight
mechanism to work but have a broken VBT indicating otherwise.
While at in sneak in a small comment cleanup too.

Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/15679
Signed-off-by: Suraj Kandpal <suraj.kandpal@intel.com>
---
 .../drm/i915/display/intel_dp_aux_backlight.c | 19 +++++++------------
 1 file changed, 7 insertions(+), 12 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 eb05ef4bd9f6..a8e9872566cd 100644
--- a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
@@ -644,9 +644,10 @@ int intel_dp_aux_init_backlight_funcs(struct intel_connector *connector)
 	struct intel_dp *intel_dp = intel_attached_dp(connector);
 	struct drm_device *dev = connector->base.dev;
 	struct intel_panel *panel = &connector->panel;
-	bool try_intel_interface = false, try_vesa_interface = false;
+	bool try_intel_interface = false;
 
-	/* Check the VBT and user's module parameters to figure out which
+	/*
+	 * Check the VBT and user's module parameters to figure out which
 	 * interfaces to probe
 	 */
 	switch (display->params.enable_dpcd_backlight) {
@@ -655,7 +656,6 @@ int intel_dp_aux_init_backlight_funcs(struct intel_connector *connector)
 	case INTEL_DP_AUX_BACKLIGHT_AUTO:
 		switch (panel->vbt.backlight.type) {
 		case INTEL_BACKLIGHT_VESA_EDP_AUX_INTERFACE:
-			try_vesa_interface = true;
 			break;
 		case INTEL_BACKLIGHT_DISPLAY_DDI:
 			try_intel_interface = true;
@@ -668,20 +668,12 @@ int intel_dp_aux_init_backlight_funcs(struct intel_connector *connector)
 		if (panel->vbt.backlight.type != INTEL_BACKLIGHT_VESA_EDP_AUX_INTERFACE)
 			try_intel_interface = true;
 
-		try_vesa_interface = true;
-		break;
-	case INTEL_DP_AUX_BACKLIGHT_FORCE_VESA:
-		try_vesa_interface = true;
 		break;
 	case INTEL_DP_AUX_BACKLIGHT_FORCE_INTEL:
 		try_intel_interface = true;
 		break;
 	}
 
-	/* For eDP 1.5 and above we are supposed to use VESA interface for brightness control */
-	if (intel_dp->edp_dpcd[0] >= DP_EDP_15)
-		try_vesa_interface = true;
-
 	/*
 	 * Since Intel has their own backlight control interface, the majority of machines out there
 	 * using DPCD backlight controls with Intel GPUs will be using this interface as opposed to
@@ -694,6 +686,9 @@ int intel_dp_aux_init_backlight_funcs(struct intel_connector *connector)
 	 * panel with Intel's OUI - which is also required for us to be able to detect Intel's
 	 * backlight interface at all. This means that the only sensible way for us to detect both
 	 * interfaces is to probe for Intel's first, and VESA's second.
+	 *
+	 * Also there is a chance some VBT's may advertise false Intel backlight support even if the
+	 * tcon's DPCD says otherwise. This mean we keep VESA interface as fallback in that case.
 	 */
 	if (try_intel_interface && intel_dp_aux_supports_hdr_backlight(connector) &&
 	    intel_dp->edp_dpcd[0] <= DP_EDP_14b) {
@@ -703,7 +698,7 @@ int intel_dp_aux_init_backlight_funcs(struct intel_connector *connector)
 		return 0;
 	}
 
-	if (try_vesa_interface && intel_dp_aux_supports_vesa_backlight(connector)) {
+	if (intel_dp_aux_supports_vesa_backlight(connector)) {
 		drm_dbg_kms(dev, "[CONNECTOR:%d:%s] Using VESA eDP backlight controls\n",
 			    connector->base.base.id, connector->base.name);
 		panel->backlight.funcs = &intel_dp_vesa_bl_funcs;
-- 
2.34.1


^ permalink raw reply related	[flat|nested] 10+ messages in thread
end of thread, other threads:[~2026-04-14 15:45 UTC | newest]

Thread overview: 10+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2026-02-24  3:13 [PATCH] drm/i915/backlight: Remove try_vesa_interface Suraj Kandpal
2026-02-24  3:20 ` ✓ CI.KUnit: success for " Patchwork
2026-02-26  4:55 ` [PATCH] " Nautiyal, Ankit K
2026-03-31 23:35 ` Ville Syrjälä
2026-04-01  3:07   ` Kandpal, Suraj
2026-04-01  3:25     ` Kandpal, Suraj
2026-04-01  3:44       ` Kandpal, Suraj
2026-04-13 23:09 ` Werner Sembach
2026-04-14  6:11   ` Kandpal, Suraj
2026-04-14 15:45     ` Werner Sembach

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