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

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Message-ID: <fba1e0d4-105f-4a1e-8aab-388b5af864b0@quicinc.com>
Date: Wed, 19 Jun 2024 15:13:17 -0700
From: Jessica Zhang <quic_jesszhan@...cinc.com>
To: Dmitry Baryshkov <dmitry.baryshkov@...aro.org>,
        Rob Clark
	<robdclark@...il.com>,
        Abhinav Kumar <quic_abhinavk@...cinc.com>,
        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: Re: [PATCH v2 13/14] drm/msm/hdmi: ensure that HDMI is one if HPD is
 requested



On 5/22/2024 3:51 AM, Dmitry Baryshkov wrote:
> 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>

Reviewed-by: Jessica Zhang <quic_jesszhan@...cinc.com>

> ---
>   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
>