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FAILED: patch "[PATCH] drm/i915: Pick the backlight controller based on VBT on ICP+" failed to apply to 6.1-stable tree

PATCH [email protected] 1 participant 1 message May 13, 2023

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Stable branch DRM drivers Intel i915 Intel DRM display for xe and i915 drivers
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The patch below does not apply to the 6.1-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y
git checkout FETCH_HEAD
git cherry-pick -x b33771546309b46b681388b3540b69a75a0e2e69
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2023051321-curable-estimate-ab52@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..

Possible dependencies:

b33771546309 ("drm/i915: Pick the backlight controller based on VBT on ICP+")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From b33771546309b46b681388b3540b69a75a0e2e69 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= <[email protected]>
Date: Tue, 7 Feb 2023 08:43:37 +0200
Subject: [PATCH] drm/i915: Pick the backlight controller based on VBT on ICP+
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Use the second backlight controller on ICP+ if the VBT asks us to do so.

On pre-MTP we also check the chicken bit to make sure the pins have been correctly muxed by the firmware.

Cc [email protected]
Closes https://gitlab.freedesktop.org/drm/intel/-/issues/8016
Signed-off-by Ville Syrjälä <[email protected]>
Link https://patchwork.freedesktop.org/patch/msgid/[email protected]
Reviewed-by Jani Nikula <[email protected]>
drivers/gpu/drm/i915/display/intel_backlight.c +31 -3
index 5b7da72c95b8..a4e4b7f79e4d 100644
@@ -1431,6 +1431,30 @@ bxt_setup_backlight(struct intel_connector *connector, enum pipe unused)
 	return 0;
 }
 
+static int cnp_num_backlight_controllers(struct drm_i915_private *i915)
+{
+	if (INTEL_PCH_TYPE(i915) >= PCH_DG1)
+		return 1;
+
+	if (INTEL_PCH_TYPE(i915) >= PCH_ICP)
+		return 2;
+
+	return 1;
+}
+
+static bool cnp_backlight_controller_is_valid(struct drm_i915_private *i915, int controller)
+{
+	if (controller < 0 || controller >= cnp_num_backlight_controllers(i915))
+		return false;
+
+	if (controller == 1 &&
+	    INTEL_PCH_TYPE(i915) >= PCH_ICP &&
+	    INTEL_PCH_TYPE(i915) < PCH_MTP)
+		return intel_de_read(i915, SOUTH_CHICKEN1) & ICP_SECOND_PPS_IO_SELECT;
+
+	return true;
+}
+
 static int
 cnp_setup_backlight(struct intel_connector *connector, enum pipe unused)
 {

@@ -1440,10 +1464,14 @@ cnp_setup_backlight(struct intel_connector *connector, enum pipe unused)
 
 	/*
 	 * CNP has the BXT implementation of backlight, but with only one
-	 * controller. TODO: ICP has multiple controllers but we only use
-	 * controller 0 for now.
+	 * controller. ICP+ can have two controllers, depending on pin muxing.
 	 */
-	panel->backlight.controller = 0;
+	panel->backlight.controller = connector->panel.vbt.backlight.controller;
+	if (!cnp_backlight_controller_is_valid(i915, panel->backlight.controller)) {
+		drm_dbg_kms(&i915->drm, "Invalid backlight controller %d, assuming 0\n",
+			    panel->backlight.controller);
+		panel->backlight.controller = 0;
+	}
 
 	pwm_ctl = intel_de_read(i915,
 				BXT_BLC_PWM_CTL(panel->backlight.controller));