Re: [PATCH v6 09/22] drm: bridge: dw_hdmi: Invalidate CEC phys addr from connector detect

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] Moving CEC physical address invalidation exclusively to dw_hdmi_connector_detect breaks CEC functionality when dw_hdmi operates purely as a DRM bridge.
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commit 05206110d2cbe02dc5e2cae3b6c3e7d2d8cdbe48
Author: Jonas Karlman <jonas@kwiboo.se>
Subject: drm: bridge: dw_hdmi: Invalidate CEC phys addr from connector detect

This commit delays the CEC physical address invalidation from the IRQ
handler until the connector detect operation is called.

> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> index 5fd26ff8f55b4..aae1b890167b1 100644
> --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> @@ -2472,7 +2472,17 @@ dw_hdmi_connector_detect(struct drm_connector *connector, bool force)
>  {
>  	struct dw_hdmi *hdmi = container_of(connector, struct dw_hdmi,
>  					     connector);
> -	return dw_hdmi_detect(hdmi);
> +	enum drm_connector_status status;
> +
> +	status = dw_hdmi_detect(hdmi);
> +
> +	if (status == connector_status_disconnected) {
> +		mutex_lock(&hdmi->cec_notifier_mutex);
> +		cec_notifier_phys_addr_invalidate(hdmi->cec_notifier);
> +		mutex_unlock(&hdmi->cec_notifier_mutex);
> +	}
> +
> +	return status;
>  }

Does moving the invalidation exclusively to dw_hdmi_connector_detect break
CEC functionality when the hardware operates purely as a DRM bridge?

Before this change, cec_notifier_phys_addr_invalidate was called directly
from the hardware interrupt handler, guaranteeing execution on disconnect
regardless of how the driver was configured.

In bridge-only mode, the connector is created externally and
dw_hdmi_connector_detect is never executed. The DRM core or downstream
component instead calls dw_hdmi_bridge_detect, which was not updated here
to include the CEC invalidation logic. The CEC physical address might not
be invalidated on unplug in bridge mode, which would be a regression.

I see this is addressed later in the series by commit 795c172faddab (drm:
bridge: dw_hdmi: Update EDID and CEC phys addr in bridge detect()), but
this intermediate patch appears to introduce a functional regression that
might affect bisection.

[ ... ]

> @@ -3106,12 +3116,6 @@ 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) {
> -			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) &&
>  		    (phy_stat & HDMI_PHY_HPD))
>  			status = connector_status_connected;

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Sashiko AI review · https://sashiko.dev/#/patchset/20260516183838.2024991-1-jonas@kwiboo.se?part=9