Re: [PATCH v2] platform/chrome: cros_ec_ishtp: report EC_HOST_EVENT_PANIC to userspace

[Tzung-Bi Shih <tzungbi@kernel.org>]

On Wed, Oct 28, 2026 at 03:04:14PM -0700, Scott Collyer wrote:
> +static int cros_ec_ishtp_event(struct notifier_block *nb,
> +			       unsigned long queued_during_suspend,
> +			       void *data)
> +{
> +	struct ishtp_cl_data *client_data =
> +		container_of(nb, struct ishtp_cl_data, notifier);
> +	struct cros_ec_device *ec_dev = data;
> +	u32 host_event = cros_ec_get_host_event(ec_dev);
> +
> +	if (host_event & EC_HOST_EVENT_MASK(EC_HOST_EVENT_PANIC)) {
> +		static const char * const panic_env[] = { "ERROR=PANIC", NULL };
> +
> +		dev_emerg(cl_data_to_dev(client_data), "CrOS ISH Panic Reported\n");

Use `ec_dev->dev` instead of `cl_data_to_dev(client_data)` so that the
`client_data` lookup can be dropped.

> @@ -555,7 +581,20 @@ static int cros_ec_dev_init(struct ishtp_cl_data *client_data)
>  	ec_dev->pkt_xfer = cros_ec_pkt_xfer_ish;
>  	ec_dev->phys_name = dev_name(dev);
>  
> -	return cros_ec_register(ec_dev);
> +	rv = cros_ec_register(ec_dev);
> +	if (rv)
> +		return rv;
> +
> +	client_data->notifier.notifier_call = cros_ec_ishtp_event;
> +	rv = blocking_notifier_chain_register(&ec_dev->event_notifier,
> +					      &client_data->notifier);
> +	if (rv) {
> +		dev_warn(dev, "failed to setup event notifier: %d\n", rv);
> +		cros_ec_unregister(ec_dev);
> +		return rv;
> +	}

cros_ec_register() already starts dispatching pending events before it
returns, so there is a small window where the notifier could miss them.
Please register the notifier before calling cros_ec_register().