Re: [PATCH v23 09/13] mfd: psci-mfd: Add psci-reboot-mode child cell

On 14-07-2026 22:54, [email protected] wrote:
> Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
> - [High] The probe function `psci_mfd_probe` ignores the return value of `devm_mfd_add_devices()` for the `psci_reboot_mode_cell` child device, violating the MFD subsystem guideline requiring probe failures to be propagated and unwound.
> --
> 
> --- Patch [9]: [PATCH v23 09/13] mfd: psci-mfd: Add psci-reboot-mode child cell ---
> commit 73724460c58fad980d9dd8ef39b9485acffad30e
> Author: Shivendra Pratap <[email protected]>
> 
> mfd: psci-mfd: Add psci-reboot-mode child cell
> 
> This commit adds the psci-reboot-mode child cell to the psci-mfd driver.
> It retrieves the reboot-mode firmware node and registers the new cell
> using devm_mfd_add_devices if the node is present.
> 
>> diff --git a/drivers/mfd/psci-mfd.c b/drivers/mfd/psci-mfd.c
>> index 7affd6bb09dd8..8c6b78ac471bf 100644
>> --- a/drivers/mfd/psci-mfd.c
>> +++ b/drivers/mfd/psci-mfd.c
> 
> [ ... ]
> 
>> @@ -14,10 +15,37 @@ static const struct mfd_cell psci_cells[] = {
>>   	},
>>   };
>>   
>> +static const struct mfd_cell psci_reboot_mode_cell[] = {
>> +	{
>> +		.name = "psci-reboot-mode",
>> +		.named_fwnode = "reboot-mode",
>> +	},
>> +};
>> +
>>   static int psci_mfd_probe(struct platform_device *pdev)
>>   {
>> -	return devm_mfd_add_devices(&pdev->dev, PLATFORM_DEVID_AUTO, psci_cells,
>> +	struct fwnode_handle *fwnode;
>> +	int ret;
>> +
>> +	ret = devm_mfd_add_devices(&pdev->dev, PLATFORM_DEVID_AUTO, psci_cells,
>>   				   ARRAY_SIZE(psci_cells), NULL, 0, NULL);
>> +	if (ret)
>> +		return ret;
>> +
>> +	fwnode = device_get_named_child_node(&pdev->dev, "reboot-mode");
>> +	if (!fwnode)
>> +		return 0;
>> +
>> +	fwnode_handle_put(fwnode);
>> +
>> +	ret = devm_mfd_add_devices(&pdev->dev, PLATFORM_DEVID_AUTO,
>> +				   psci_reboot_mode_cell,
>> +				   ARRAY_SIZE(psci_reboot_mode_cell),
>> +				   NULL, 0, NULL);
>> +	if (ret)
>> +		dev_warn(&pdev->dev, "reboot-mode child cell failed to add: %d\n", ret);
>> +
>> +	return 0;
> 
> [Severity: High]
> Should this propagate the error code instead of returning 0?
> 
> The MFD subsystem guidelines specify that if a child device fails to register
> during probe, the entire probe must fail and unwind previously registered
> children. By returning 0 here, the MFD device is left in a partially
> initialized state if the psci-reboot-mode cell fails to register.

the cpu-idle-domain is a mandatory driver. We do not want to fail 
psci-mfd for any probe failures in reboot-mode probe and unwind the 
cpu-idle-domain driver. Have documented in commit text.

thanks,
Shivendra