Re: [PATCH v2 2/4] firmware: arm_scmi: Skip requests for standard protocol devices

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] arm_scmi: dead code in scmi_device_create() for standard devices
--

commit cb938ad959a8195c8129d8e6f7596ff9fd2ddff8
Author: Sudeep Holla <sudeep.holla@kernel.org>

firmware: arm_scmi: Skip requests for standard protocol devices

The SCMI core skips request tracking for standard protocol devices to avoid
issues when unregistered drivers destroy the core-created device. Keep
request tracking and rollback for nonstandard devices unchanged.

> diff --git a/drivers/firmware/arm_scmi/bus.c b/drivers/firmware/arm_scmi/bus.c
> index f2e2ed56bc326..230ee9f6f1aa5 100644
> --- a/drivers/firmware/arm_scmi/bus.c
> +++ b/drivers/firmware/arm_scmi/bus.c
> @@ -186,12 +186,44 @@ static void scmi_protocol_device_unrequest(const struct scmi_device_id *id_table
[ ... ]
>  static int scmi_protocol_table_register(const struct scmi_device_id *id_table)
>  {
>  	const struct scmi_device_id *entry;
>  	int ret;
>  
>  	for (entry = id_table; entry->name[0]; entry++) {
> +		/* Skip standard devices as they are created unconditionally */
> +		if (scmi_device_id_in_std_id_table(entry))
> +			continue;
> +
>  		ret = scmi_protocol_device_request(entry);
>  		if (ret)
>  			goto err_unrequest;

[Severity: Low]
Does this change make the check for standard devices in scmi_device_create()
obsolete?

Since standard devices are no longer passed to scmi_protocol_device_request(),
they aren't added to the scmi_requested_devices IDR. When scmi_device_create()
subsequently walks the requested list, phead will only contain non-standard
devices:

drivers/firmware/arm_scmi/bus.c:scmi_device_create() {
    ...
	/* Walk the list of requested devices for protocol and create them */
	list_for_each_entry(rdev, phead, node) {
		/* Standard proto matches already have their dev created above */
		if (scmi_device_id_in_std_id_table(rdev->id_table))
			continue;
    ...
}

Will this check in scmi_device_create() always evaluate to false now, making
it dead code?

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261005-scmi_bus_fixes-v2-0-34a51338875a@kernel.org?part=2