From 48fd60f3bd8da3cf27db0a8496339846134c8aa1 Mon Sep 17 00:00:00 2001
From: kettenis <kettenis@openbsd.org>
Date: Tue, 23 Jan 2024 15:48:28 +0000
Subject: [PATCH] drm: apple: backlight: force backlight update after resume

From Mark Kettenis
fcad9f366ba0c934f877662ee8199051b636d2e1 in jannau's bits/200-dcp
---
 sys/dev/pci/drm/apple/dcp-internal.h   |  3 +++
 sys/dev/pci/drm/apple/dcp.c            | 10 +++++++++
 sys/dev/pci/drm/apple/dcp_backlight.c  | 31 +++++++++++++++-----------
 sys/dev/pci/drm/apple/iomfb_template.c |  1 +
 4 files changed, 32 insertions(+), 13 deletions(-)

diff --git a/sys/dev/pci/drm/apple/dcp-internal.h b/sys/dev/pci/drm/apple/dcp-internal.h
index 55d6303599d..a8425daea0f 100644
--- a/sys/dev/pci/drm/apple/dcp-internal.h
+++ b/sys/dev/pci/drm/apple/dcp-internal.h
@@ -212,6 +212,8 @@ struct apple_dcp {
 	/* Workqueue for updating the initial initial brightness */
 	struct work_struct bl_register_wq;
 	struct rwlock bl_register_mutex;
+	/* Workqueue for updating the brightness */
+	struct work_struct bl_update_wq;
 
 	/* integrated panel if present */
 	struct dcp_panel panel;
@@ -241,6 +243,7 @@ struct apple_dcp {
 };
 
 int dcp_backlight_register(struct apple_dcp *dcp);
+int dcp_backlight_update(struct apple_dcp *dcp);
 bool dcp_has_panel(struct apple_dcp *dcp);
 
 #define DCP_AUDIO_MAX_CHANS 15
diff --git a/sys/dev/pci/drm/apple/dcp.c b/sys/dev/pci/drm/apple/dcp.c
index 6eb2d552299..bf797bc8d97 100644
--- a/sys/dev/pci/drm/apple/dcp.c
+++ b/sys/dev/pci/drm/apple/dcp.c
@@ -516,6 +516,15 @@ out_unlock:
 	mutex_unlock(&dcp->bl_register_mutex);
 }
 
+static void dcp_work_update_backlight(struct work_struct *work)
+{
+	struct apple_dcp *dcp;
+
+	dcp = container_of(work, struct apple_dcp, bl_update_wq);
+
+	dcp_backlight_update(dcp);
+}
+
 static int dcp_create_piodma_iommu_dev(struct apple_dcp *dcp)
 {
 	int ret;
@@ -836,6 +845,7 @@ static int dcp_comp_bind(struct device *dev, struct device *main, void *data)
 		dcp->connector_type = DRM_MODE_CONNECTOR_eDP;
 		INIT_WORK(&dcp->bl_register_wq, dcp_work_register_backlight);
 		rw_init(&dcp->bl_register_mutex, "dcpbl");
+		INIT_WORK(&dcp->bl_update_wq, dcp_work_update_backlight);
 	} else if (of_property_match_string(dev->of_node, "apple,connector-type", "HDMI-A") >= 0)
 		dcp->connector_type = DRM_MODE_CONNECTOR_HDMIA;
 	else if (of_property_match_string(dev->of_node, "apple,connector-type", "DP") >= 0)
diff --git a/sys/dev/pci/drm/apple/dcp_backlight.c b/sys/dev/pci/drm/apple/dcp_backlight.c
index d3e9a33b79e..54bbaec6335 100644
--- a/sys/dev/pci/drm/apple/dcp_backlight.c
+++ b/sys/dev/pci/drm/apple/dcp_backlight.c
@@ -172,20 +172,8 @@ done:
 	return ret;
 }
 
-static int dcp_set_brightness(struct backlight_device *bd)
+int dcp_backlight_update(struct apple_dcp *dcp)
 {
-	int ret = 0;
-	struct apple_dcp *dcp = bl_get_data(bd);
-	struct drm_modeset_acquire_ctx ctx;
-	int brightness = backlight_get_brightness(bd);
-
-	DRM_MODESET_LOCK_ALL_BEGIN(dcp->crtc->base.dev, ctx, 0, ret);
-
-	dcp->brightness.dac = calculate_dac(dcp, brightness);
-	dcp->brightness.update = true;
-
-	DRM_MODESET_LOCK_ALL_END(dcp->crtc->base.dev, ctx, ret);
-
 	/*
 	 * Do not actively try to change brightness if no mode is set.
 	 * TODO: should this be reflected the in backlight's power property?
@@ -202,6 +190,23 @@ static int dcp_set_brightness(struct backlight_device *bd)
 	return drm_crtc_set_brightness(dcp);
 }
 
+static int dcp_set_brightness(struct backlight_device *bd)
+{
+	int ret = 0;
+	struct apple_dcp *dcp = bl_get_data(bd);
+	struct drm_modeset_acquire_ctx ctx;
+	int brightness = backlight_get_brightness(bd);
+
+	DRM_MODESET_LOCK_ALL_BEGIN(dcp->crtc->base.dev, ctx, 0, ret);
+
+	dcp->brightness.dac = calculate_dac(dcp, brightness);
+	dcp->brightness.update = true;
+
+	DRM_MODESET_LOCK_ALL_END(dcp->crtc->base.dev, ctx, ret);
+
+	return dcp_backlight_update(dcp);
+}
+
 static const struct backlight_ops dcp_backlight_ops = {
 	.options = BL_CORE_SUSPENDRESUME,
 	.get_brightness = dcp_get_brightness,
diff --git a/sys/dev/pci/drm/apple/iomfb_template.c b/sys/dev/pci/drm/apple/iomfb_template.c
index 7c8dc5a25d1..c2f8dc003c4 100644
--- a/sys/dev/pci/drm/apple/iomfb_template.c
+++ b/sys/dev/pci/drm/apple/iomfb_template.c
@@ -497,6 +497,7 @@ static void iomfbep_cb_enable_backlight_message_ap_gated(struct apple_dcp *dcp,
 	 * syslog: "[BrightnessLCD.cpp:743][AFK]nitsToDBV: iDAC out of range"
 	 */
 	dcp->brightness.update = true;
+	schedule_work(&dcp->bl_update_wq);
 }
 
 /* Chunked data transfer for property dictionaries */
-- 
2.20.1