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

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.

>  }
>  
>  static const struct of_device_id psci_mfd_of_match[] = {

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260714-arm-psci-system_reset2-vendor-reboots-v23-0-e7453c548c21@oss.qualcomm.com?part=9