linux-kernel - [PATCH v2 13/14] drm/msm/hdmi: ensure that HDMI is one if HPD is requested

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Message-Id: <20240522-fd-hdmi-hpd-v2-13-c30bdb7c5c7e@linaro.org>
Date: Wed, 22 May 2024 13:51:05 +0300
From: Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
To: Rob Clark <robdclark@...il.com>, 
 Abhinav Kumar <quic_abhinavk@...cinc.com>, 
 Dmitry Baryshkov <dmitry.baryshkov@...aro.org>, Sean Paul <sean@...rly.run>, 
 Marijn Suijten <marijn.suijten@...ainline.org>, 
 David Airlie <airlied@...il.com>, Daniel Vetter <daniel@...ll.ch>
Cc: linux-arm-msm@...r.kernel.org, dri-devel@...ts.freedesktop.org, 
 freedreno@...ts.freedesktop.org, linux-kernel@...r.kernel.org
Subject: [PATCH v2 13/14] drm/msm/hdmi: ensure that HDMI is one if HPD is
 requested

The HDMI block needs to be enabled to properly generate HPD events. Make
sure it is not turned off in the disable paths if HPD delivery is enabled.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
---
 drivers/gpu/drm/msm/hdmi/hdmi.c        | 1 +
 drivers/gpu/drm/msm/hdmi/hdmi.h        | 2 ++
 drivers/gpu/drm/msm/hdmi/hdmi_bridge.c | 8 +++++++-
 drivers/gpu/drm/msm/hdmi/hdmi_hpd.c    | 9 ++++++++-
 4 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/msm/hdmi/hdmi.c b/drivers/gpu/drm/msm/hdmi/hdmi.c
index a9437054c015..2890196857f8 100644
--- a/drivers/gpu/drm/msm/hdmi/hdmi.c
+++ b/drivers/gpu/drm/msm/hdmi/hdmi.c
@@ -409,6 +409,7 @@ static int msm_hdmi_dev_probe(struct platform_device *pdev)
 	hdmi->pdev = pdev;
 	hdmi->config = config;
 	spin_lock_init(&hdmi->reg_lock);
+	mutex_init(&hdmi->state_mutex);
 
 	ret = drm_of_find_panel_or_bridge(pdev->dev.of_node, 1, 0, NULL, &hdmi->next_bridge);
 	if (ret && ret != -ENODEV)
diff --git a/drivers/gpu/drm/msm/hdmi/hdmi.h b/drivers/gpu/drm/msm/hdmi/hdmi.h
index 268ff8604423..7f0ca5252018 100644
--- a/drivers/gpu/drm/msm/hdmi/hdmi.h
+++ b/drivers/gpu/drm/msm/hdmi/hdmi.h
@@ -42,6 +42,8 @@ struct hdmi {
 
 	/* video state: */
 	bool power_on;
+	bool hpd_enabled;
+	struct mutex state_mutex; /* protects two booleans */
 	unsigned long int pixclock;
 
 	void __iomem *mmio;
diff --git a/drivers/gpu/drm/msm/hdmi/hdmi_bridge.c b/drivers/gpu/drm/msm/hdmi/hdmi_bridge.c
index cddba640d292..104107ed47d0 100644
--- a/drivers/gpu/drm/msm/hdmi/hdmi_bridge.c
+++ b/drivers/gpu/drm/msm/hdmi/hdmi_bridge.c
@@ -117,11 +117,13 @@ static void msm_hdmi_bridge_atomic_pre_enable(struct drm_bridge *bridge,
 
 	DBG("power up");
 
+	mutex_lock(&hdmi->state_mutex);
 	if (!hdmi->power_on) {
 		msm_hdmi_phy_resource_enable(phy);
 		msm_hdmi_power_on(bridge);
 		hdmi->power_on = true;
 	}
+	mutex_unlock(&hdmi->state_mutex);
 
 	if (hdmi->hdmi_mode) {
 		msm_hdmi_config_avi_infoframe(hdmi);
@@ -147,7 +149,10 @@ static void msm_hdmi_bridge_atomic_post_disable(struct drm_bridge *bridge,
 		msm_hdmi_hdcp_off(hdmi->hdcp_ctrl);
 
 	DBG("power down");
-	msm_hdmi_set_mode(hdmi, false);
+
+	/* Keep the HDMI enabled if the HPD is enabled */
+	mutex_lock(&hdmi->state_mutex);
+	msm_hdmi_set_mode(hdmi, hdmi->hpd_enabled);
 
 	msm_hdmi_phy_powerdown(phy);
 
@@ -158,6 +163,7 @@ static void msm_hdmi_bridge_atomic_post_disable(struct drm_bridge *bridge,
 			msm_hdmi_audio_update(hdmi);
 		msm_hdmi_phy_resource_disable(phy);
 	}
+	mutex_unlock(&hdmi->state_mutex);
 }
 
 static void msm_hdmi_bridge_mode_set(struct drm_bridge *bridge,
diff --git a/drivers/gpu/drm/msm/hdmi/hdmi_hpd.c b/drivers/gpu/drm/msm/hdmi/hdmi_hpd.c
index d3353c6148ed..cb89e9e2c6ea 100644
--- a/drivers/gpu/drm/msm/hdmi/hdmi_hpd.c
+++ b/drivers/gpu/drm/msm/hdmi/hdmi_hpd.c
@@ -73,10 +73,14 @@ int msm_hdmi_hpd_enable(struct drm_bridge *bridge)
 	if (ret)
 		return ret;
 
+	mutex_lock(&hdmi->state_mutex);
 	msm_hdmi_set_mode(hdmi, false);
 	msm_hdmi_phy_reset(hdmi);
 	msm_hdmi_set_mode(hdmi, true);
 
+	hdmi->hpd_enabled = true;
+	mutex_unlock(&hdmi->state_mutex);
+
 	hdmi_write(hdmi, REG_HDMI_USEC_REFTIMER, 0x0001001b);
 
 	/* enable HPD events: */
@@ -106,7 +110,10 @@ void msm_hdmi_hpd_disable(struct hdmi *hdmi)
 	/* Disable HPD interrupt */
 	hdmi_write(hdmi, REG_HDMI_HPD_INT_CTRL, 0);
 
-	msm_hdmi_set_mode(hdmi, false);
+	mutex_lock(&hdmi->state_mutex);
+	hdmi->hpd_enabled = false;
+	msm_hdmi_set_mode(hdmi, hdmi->power_on);
+	mutex_unlock(&hdmi->state_mutex);
 
 	pm_runtime_put(dev);
 }

-- 
2.39.2