openwrt/target/linux/bcm27xx/patches-5.15/950-0580-drm-vc4-Ensure-vc4_hdmi-doesn-t-use-2711-HPD-registe.patch

From 3542a39c5655242ba89bb4f51e9237cbb7e8cf09 Mon Sep 17 00:00:00 2001
From: Dave Stevenson <dave.stevenson@raspberrypi.com>
Date: Fri, 19 Nov 2021 16:16:40 +0000
Subject: [PATCH] drm/vc4: Ensure vc4_hdmi doesn't use 2711 HPD
 registers on Pi0-3

The existing logic was flawed in that it could try reading the
2711 specific registers for HPD on a CM1/3 where the HPD GPIO
hadn't been defined in DT.

Ensure we don't do the 2711 register read on invalid hardware,
and then

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
---
 drivers/gpu/drm/vc4/vc4_hdmi.c | 24 ++++++++++++++++--------
 drivers/gpu/drm/vc4/vc4_hdmi.h |  3 +++
 2 files changed, 19 insertions(+), 8 deletions(-)

--- a/drivers/gpu/drm/vc4/vc4_hdmi.c
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
@@ -206,14 +206,8 @@ vc4_hdmi_connector_detect(struct drm_con
 		if (gpiod_get_value_cansleep(vc4_hdmi->hpd_gpio))
 			connected = true;
 	} else {
-		unsigned long flags;
-		u32 hotplug;
-
-		spin_lock_irqsave(&vc4_hdmi->hw_lock, flags);
-		hotplug = HDMI_READ(HDMI_HOTPLUG);
-		spin_unlock_irqrestore(&vc4_hdmi->hw_lock, flags);
-
-		if (hotplug & VC4_HDMI_HOTPLUG_CONNECTED)
+		if (vc4_hdmi->variant->hp_detect &&
+		    vc4_hdmi->variant->hp_detect(vc4_hdmi))
 			connected = true;
 	}
 
@@ -1355,6 +1349,18 @@ static u32 vc5_hdmi_channel_map(struct v
 	return channel_map;
 }
 
+static bool vc5_hdmi_hp_detect(struct vc4_hdmi *vc4_hdmi)
+{
+	unsigned long flags;
+	u32 hotplug;
+
+	spin_lock_irqsave(&vc4_hdmi->hw_lock, flags);
+	hotplug = HDMI_READ(HDMI_HOTPLUG);
+	spin_unlock_irqrestore(&vc4_hdmi->hw_lock, flags);
+
+	return !!(hotplug & VC4_HDMI_HOTPLUG_CONNECTED);
+}
+
 /* HDMI audio codec callbacks */
 static void vc4_hdmi_audio_set_mai_clock(struct vc4_hdmi *vc4_hdmi,
 					 unsigned int samplerate)
@@ -2776,6 +2782,7 @@ static const struct vc4_hdmi_variant bcm
 	.phy_rng_disable	= vc5_hdmi_phy_rng_disable,
 	.channel_map		= vc5_hdmi_channel_map,
 	.supports_hdr		= true,
+	.hp_detect		= vc5_hdmi_hp_detect,
 };
 
 static const struct vc4_hdmi_variant bcm2711_hdmi1_variant = {
@@ -2804,6 +2811,7 @@ static const struct vc4_hdmi_variant bcm
 	.phy_rng_disable	= vc5_hdmi_phy_rng_disable,
 	.channel_map		= vc5_hdmi_channel_map,
 	.supports_hdr		= true,
+	.hp_detect		= vc5_hdmi_hp_detect,
 };
 
 static const struct of_device_id vc4_hdmi_dt_match[] = {
--- a/drivers/gpu/drm/vc4/vc4_hdmi.h
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.h
@@ -102,6 +102,9 @@ struct vc4_hdmi_variant {
 
 	/* Enables HDR metadata */
 	bool supports_hdr;
+
+	/* Callback for hardware specific hotplug detect */
+	bool (*hp_detect)(struct vc4_hdmi *vc4_hdmi);
 };
 
 /* HDMI audio information */