Re: [PATCH v7 8/9] drm: dw-hdmi: use cec_notifier_conn_(un)register

[Hans Verkuil <hverkuil-cisco@xs4all.nl>]

On 8/14/19 12:45 PM, Dariusz Marcinkiewicz wrote:
> Use the new cec_notifier_conn_(un)register() functions to
> (un)register the notifier for the HDMI connector, and fill in
> the cec_connector_info.
> 
> Changes since v6:
>         - move cec_notifier_conn_unregister to a bridge detach
> 	  function,
> 	- add a mutex protecting a CEC notifier.
> Changes since v4:
> 	- typo fix
> Changes since v2:
> 	- removed unnecessary NULL check before a call to
> 	cec_notifier_conn_unregister,
> 	- use cec_notifier_phys_addr_invalidate to invalidate physical
> 	address.
> Changes since v1:
> 	Add memory barrier to make sure that the notifier
> 	becomes visible to the irq thread once it is fully
> 	constructed.
> 
> Signed-off-by: Dariusz Marcinkiewicz <darekm@google.com>

Acked-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>

Regards,

	Hans

> ---
>  drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 45 +++++++++++++++--------
>  1 file changed, 30 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> index 83b94b66e464e..55162c9092f71 100644
> --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> @@ -190,6 +190,7 @@ struct dw_hdmi {
>  	void (*enable_audio)(struct dw_hdmi *hdmi);
>  	void (*disable_audio)(struct dw_hdmi *hdmi);
>  
> +	struct mutex cec_notifier_mutex;
>  	struct cec_notifier *cec_notifier;
>  };
>  
> @@ -2194,6 +2195,8 @@ static int dw_hdmi_bridge_attach(struct drm_bridge *bridge)
>  	struct dw_hdmi *hdmi = bridge->driver_private;
>  	struct drm_encoder *encoder = bridge->encoder;
>  	struct drm_connector *connector = &hdmi->connector;
> +	struct cec_connector_info conn_info;
> +	struct cec_notifier *notifier;
>  
>  	connector->interlace_allowed = 1;
>  	connector->polled = DRM_CONNECTOR_POLL_HPD;
> @@ -2207,9 +2210,29 @@ static int dw_hdmi_bridge_attach(struct drm_bridge *bridge)
>  
>  	drm_connector_attach_encoder(connector, encoder);
>  
> +	cec_fill_conn_info_from_drm(&conn_info, connector);
> +
> +	notifier = cec_notifier_conn_register(hdmi->dev, NULL, &conn_info);
> +	if (!notifier)
> +		return -ENOMEM;
> +
> +	mutex_lock(&hdmi->cec_notifier_mutex);
> +	hdmi->cec_notifier = notifier;
> +	mutex_unlock(&hdmi->cec_notifier_mutex);
> +
>  	return 0;
>  }
>  
> +static void dw_hdmi_bridge_detach(struct drm_bridge *bridge)
> +{
> +	struct dw_hdmi *hdmi = bridge->driver_private;
> +
> +	mutex_lock(&hdmi->cec_notifier_mutex);
> +	cec_notifier_conn_unregister(hdmi->cec_notifier);
> +	hdmi->cec_notifier = NULL;
> +	mutex_unlock(&hdmi->cec_notifier_mutex);
> +}
> +
>  static enum drm_mode_status
>  dw_hdmi_bridge_mode_valid(struct drm_bridge *bridge,
>  			  const struct drm_display_mode *mode)
> @@ -2266,6 +2289,7 @@ static void dw_hdmi_bridge_enable(struct drm_bridge *bridge)
>  
>  static const struct drm_bridge_funcs dw_hdmi_bridge_funcs = {
>  	.attach = dw_hdmi_bridge_attach,
> +	.detach = dw_hdmi_bridge_detach,
>  	.enable = dw_hdmi_bridge_enable,
>  	.disable = dw_hdmi_bridge_disable,
>  	.mode_set = dw_hdmi_bridge_mode_set,
> @@ -2373,9 +2397,11 @@ static irqreturn_t dw_hdmi_irq(int irq, void *dev_id)
>  				       phy_stat & HDMI_PHY_HPD,
>  				       phy_stat & HDMI_PHY_RX_SENSE);
>  
> -		if ((phy_stat & (HDMI_PHY_RX_SENSE | HDMI_PHY_HPD)) == 0)
> -			cec_notifier_set_phys_addr(hdmi->cec_notifier,
> -						   CEC_PHYS_ADDR_INVALID);
> +		if ((phy_stat & (HDMI_PHY_RX_SENSE | HDMI_PHY_HPD)) == 0) {
> +			mutex_lock(&hdmi->cec_notifier_mutex);
> +			cec_notifier_phys_addr_invalidate(hdmi->cec_notifier);
> +			mutex_unlock(&hdmi->cec_notifier_mutex);
> +		}
>  	}
>  
>  	if (intr_stat & HDMI_IH_PHY_STAT0_HPD) {
> @@ -2561,6 +2587,7 @@ __dw_hdmi_probe(struct platform_device *pdev,
>  
>  	mutex_init(&hdmi->mutex);
>  	mutex_init(&hdmi->audio_mutex);
> +	mutex_init(&hdmi->cec_notifier_mutex);
>  	spin_lock_init(&hdmi->audio_lock);
>  
>  	ddc_node = of_parse_phandle(np, "ddc-i2c-bus", 0);
> @@ -2693,12 +2720,6 @@ __dw_hdmi_probe(struct platform_device *pdev,
>  	if (ret)
>  		goto err_iahb;
>  
> -	hdmi->cec_notifier = cec_notifier_get(dev);
> -	if (!hdmi->cec_notifier) {
> -		ret = -ENOMEM;
> -		goto err_iahb;
> -	}
> -
>  	/*
>  	 * To prevent overflows in HDMI_IH_FC_STAT2, set the clk regenerator
>  	 * N and cts values before enabling phy
> @@ -2796,9 +2817,6 @@ __dw_hdmi_probe(struct platform_device *pdev,
>  		hdmi->ddc = NULL;
>  	}
>  
> -	if (hdmi->cec_notifier)
> -		cec_notifier_put(hdmi->cec_notifier);
> -
>  	clk_disable_unprepare(hdmi->iahb_clk);
>  	if (hdmi->cec_clk)
>  		clk_disable_unprepare(hdmi->cec_clk);
> @@ -2820,9 +2838,6 @@ static void __dw_hdmi_remove(struct dw_hdmi *hdmi)
>  	/* Disable all interrupts */
>  	hdmi_writeb(hdmi, ~0, HDMI_IH_MUTE_PHY_STAT0);
>  
> -	if (hdmi->cec_notifier)
> -		cec_notifier_put(hdmi->cec_notifier);
> -
>  	clk_disable_unprepare(hdmi->iahb_clk);
>  	clk_disable_unprepare(hdmi->isfr_clk);
>  	if (hdmi->cec_clk)
>