Re: [PATCH v8 2/5] drm/scdc-helper: Add scdc_status debugfs entry

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] The function `scdc_status_show` leaks `connector->dev->mode_config.mutex` on the disconnected error path.
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--- Patch [2]: [PATCH v8 2/5] drm/scdc-helper: Add scdc_status debugfs entry ---
commit 524b3064a7221dcef8708b2269e2ccaa3ede6629
Author: Nicolas Frattaroli <[email protected]>

drm/scdc-helper: Add scdc_status debugfs entry

This commit adds a debugfs entry under the connector to expose SCDC status
information. It introduces drm_scdc_read_state to read and parse the SCDC
registers and a debugfs init function for connectors to use.

> diff --git a/drivers/gpu/drm/display/drm_scdc_helper.c b/drivers/gpu/drm/display/drm_scdc_helper.c
> index 8403f2390ab6a..97256b272329a 100644
> --- a/drivers/gpu/drm/display/drm_scdc_helper.c
> +++ b/drivers/gpu/drm/display/drm_scdc_helper.c
[ ... ]
> @@ -276,3 +278,187 @@ bool drm_scdc_set_high_tmds_clock_ratio(struct drm_connector *connector,
[ ... ]
> +static int scdc_status_show(struct seq_file *m, void *data)
> +{
> +	struct drm_connector *connector = m->private;
> +	struct drm_scdc *scdc = &connector->display_info.hdmi.scdc;
> +	struct drm_scdc_state *st;
> +	int i, ret;
> +
> +	drm_connector_get(connector);
> +
> +	ret = mutex_lock_interruptible(&connector->dev->mode_config.mutex);
> +	if (ret)
> +		goto err_conn_put;
> +
> +	if (connector->status != connector_status_connected) {
> +		ret = -ENODEV;
> +		goto err_conn_put;

[Severity: High]
Does this error path leak connector->dev->mode_config.mutex?

The mutex is successfully acquired just above this check. If the connector
is not connected, jumping directly to err_conn_put bypasses the err_unlock
label where the mutex is supposed to be released.

> +	}
> +
> +	if (scdc->supported) {
[ ... ]
> +
> +err_free_state:
> +	kfree(st);
> +err_unlock:
> +	mutex_unlock(&connector->dev->mode_config.mutex);
> +err_conn_put:
> +	drm_connector_put(connector);
> +
> +	return ret;
> +}

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Sashiko AI review · https://sashiko.dev/#/patchset/[email protected]?part=2