linux-kernel - Re: [PATCH 3/5] drm: dw-hdmi: update CEC phys addr and EDID on HPD event

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Date:   Mon, 2 Sep 2019 10:10:17 +0200
From:   Neil Armstrong <narmstrong@...libre.com>
To:     Jonas Karlman <jonas@...boo.se>,
        Andrzej Hajda <a.hajda@...sung.com>
Cc:     David Airlie <airlied@...ux.ie>, Daniel Vetter <daniel@...ll.ch>,
        Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
        Maxime Ripard <mripard@...nel.org>,
        Sean Paul <sean@...rly.run>,
        Laurent Pinchart <Laurent.pinchart@...asonboard.com>,
        Jernej Skrabec <jernej.skrabec@...l.net>,
        Hans Verkuil <hverkuil@...all.nl>,
        Jerome Brunet <jbrunet@...libre.com>,
        "dri-devel@...ts.freedesktop.org" <dri-devel@...ts.freedesktop.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 3/5] drm: dw-hdmi: update CEC phys addr and EDID on HPD
 event

On 01/09/2019 18:14, Jonas Karlman wrote:
> Update CEC phys addr and EDID on HPD event, fixes lost CEC phys addr and
> stale EDID when HDMI cable is unplugged/replugged or AVR is powered on/off.
> 
> Signed-off-by: Jonas Karlman <jonas@...boo.se>
> ---
>  drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 16 +++++++++-------
>  1 file changed, 9 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> index 91d86ddd6624..0f07be1b5914 100644
> --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> @@ -2189,6 +2189,7 @@ static int dw_hdmi_connector_update_edid(struct drm_connector *connector,
>  static enum drm_connector_status
>  dw_hdmi_connector_detect(struct drm_connector *connector, bool force)
>  {
> +	enum drm_connector_status status;
>  	struct dw_hdmi *hdmi = container_of(connector, struct dw_hdmi,
>  					     connector);
>  
> @@ -2198,7 +2199,14 @@ dw_hdmi_connector_detect(struct drm_connector *connector, bool force)
>  	dw_hdmi_update_phy_mask(hdmi);
>  	mutex_unlock(&hdmi->mutex);
>  
> -	return hdmi->phy.ops->read_hpd(hdmi, hdmi->phy.data);
> +	status = hdmi->phy.ops->read_hpd(hdmi, hdmi->phy.data);
> +
> +	if (status == connector_status_connected)
> +		dw_hdmi_connector_update_edid(connector, false);
> +	else
> +		cec_notifier_phys_addr_invalidate(hdmi->cec_notifier);
> +
> +	return status;
>  }
>  
>  static int dw_hdmi_connector_get_modes(struct drm_connector *connector)
> @@ -2438,12 +2446,6 @@ static irqreturn_t dw_hdmi_irq(int irq, void *dev_id)
>  		dw_hdmi_setup_rx_sense(hdmi,
>  				       phy_stat & HDMI_PHY_HPD,
>  				       phy_stat & HDMI_PHY_RX_SENSE);
> -
> -		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) {
> 

Won't it possibly trigger twice edid readouts on each HPD event,
one for CEC and one for modes ? It seems sane but not very efficient to me...

Anyway:
Reviewed-by: Neil Armstrong <narmstrong@...libre.com>