Re: [PATCHv2 2/4] exynos_hdmi: add HPD notifier support

[Andrzej Hajda <a.hajda@samsung.com>]

On 02.01.2017 15:19, Hans Verkuil wrote:
> From: Hans Verkuil <hans.verkuil@cisco.com>
>
> Implement the HPD notifier support to allow CEC drivers to
> be informed when there is a new EDID and when a connect or
> disconnect happens.
>
> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
> Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
> ---
>  drivers/gpu/drm/exynos/Kconfig       |  1 +
>  drivers/gpu/drm/exynos/exynos_hdmi.c | 24 +++++++++++++++++++++---
>  2 files changed, 22 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/exynos/Kconfig b/drivers/gpu/drm/exynos/Kconfig
> index d706ca4..80bfd1d 100644
> --- a/drivers/gpu/drm/exynos/Kconfig
> +++ b/drivers/gpu/drm/exynos/Kconfig
> @@ -77,6 +77,7 @@ config DRM_EXYNOS_DP
>  config DRM_EXYNOS_HDMI
>  	bool "HDMI"
>  	depends on DRM_EXYNOS_MIXER || DRM_EXYNOS5433_DECON
> +	select HPD_NOTIFIERS
>  	help
>  	  Choose this option if you want to use Exynos HDMI for DRM.
>  
> diff --git a/drivers/gpu/drm/exynos/exynos_hdmi.c b/drivers/gpu/drm/exynos/exynos_hdmi.c
> index 5ed8b1e..28bf609 100644
> --- a/drivers/gpu/drm/exynos/exynos_hdmi.c
> +++ b/drivers/gpu/drm/exynos/exynos_hdmi.c
> @@ -31,6 +31,7 @@
>  #include <linux/pm_runtime.h>
>  #include <linux/clk.h>
>  #include <linux/gpio/consumer.h>
> +#include <linux/hpd-notifier.h>
>  #include <linux/regulator/consumer.h>
>  #include <linux/io.h>
>  #include <linux/of_address.h>
> @@ -118,6 +119,7 @@ struct hdmi_context {
>  	bool				dvi_mode;
>  	struct delayed_work		hotplug_work;
>  	struct drm_display_mode		current_mode;
> +	struct hpd_notifier		*notifier;
>  	const struct hdmi_driver_data	*drv_data;
>  
>  	void __iomem			*regs;
> @@ -807,9 +809,12 @@ static enum drm_connector_status hdmi_detect(struct drm_connector *connector,
>  {
>  	struct hdmi_context *hdata = connector_to_hdmi(connector);
>  
> -	if (gpiod_get_value(hdata->hpd_gpio))
> +	if (gpiod_get_value(hdata->hpd_gpio)) {
> +		hpd_event_connect(hdata->notifier);
>  		return connector_status_connected;
> +	}
>  
> +	hpd_event_disconnect(hdata->notifier);
>  	return connector_status_disconnected;
>  }
>  
> @@ -848,6 +853,9 @@ static int hdmi_get_modes(struct drm_connector *connector)
>  		edid->width_cm, edid->height_cm);
>  
>  	drm_mode_connector_update_edid_property(connector, edid);
> +	hpd_event_connect(hdata->notifier);

Is there a reason to call hpd_event_connect here? It was called already
from hdmi_detect.

Regards
Andrzej

> +	hpd_event_new_edid(hdata->notifier, edid,
> +			    EDID_LENGTH * (1 + edid->extensions));
>  
>  	ret = drm_add_edid_modes(connector, edid);
>  
> @@ -1483,6 +1491,7 @@ static void hdmi_disable(struct drm_encoder *encoder)
>  	if (funcs && funcs->disable)
>  		(*funcs->disable)(crtc);
>  
> +	hpd_event_disconnect(hdata->notifier);
>  	cancel_delayed_work(&hdata->hotplug_work);
>  
>  	hdmiphy_disable(hdata);
> @@ -1832,15 +1841,22 @@ static int hdmi_probe(struct platform_device *pdev)
>  		}
>  	}
>  
> +	hdata->notifier = hpd_notifier_get(&pdev->dev);
> +	if (hdata->notifier == NULL) {
> +		ret = -ENOMEM;
> +		goto err_hdmiphy;
> +	}
> +
>  	pm_runtime_enable(dev);
>  
>  	ret = component_add(&pdev->dev, &hdmi_component_ops);
>  	if (ret)
> -		goto err_disable_pm_runtime;
> +		goto err_notifier_put;
>  
>  	return ret;
>  
> -err_disable_pm_runtime:
> +err_notifier_put:
> +	hpd_notifier_put(hdata->notifier);
>  	pm_runtime_disable(dev);
>  
>  err_hdmiphy:
> @@ -1859,9 +1875,11 @@ static int hdmi_remove(struct platform_device *pdev)
>  	struct hdmi_context *hdata = platform_get_drvdata(pdev);
>  
>  	cancel_delayed_work_sync(&hdata->hotplug_work);
> +	hpd_event_disconnect(hdata->notifier);
>  
>  	component_del(&pdev->dev, &hdmi_component_ops);
>  
> +	hpd_notifier_put(hdata->notifier);
>  	pm_runtime_disable(&pdev->dev);
>  
>  	if (!IS_ERR(hdata->reg_hdmi_en))