Re: [PATCH v3 2/3] misc: tc9564: introduce base PCI driver

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] tc9564: missing Kconfig dependencies on OF and PCI_DYNAMIC_OF_NODES
--

commit e821d4f3b3a6f26cf2df684fa3788ceb3794a058
Author: Alex Elder <elder@riscstar.com>
Subject: misc: tc9564: introduce base PCI driver

This commit introduces a base PCI driver for the Toshiba TC9564 SoC. It binds
with embedded PCIe endpoint functions within the chip to perform basic PCI
initialization. The driver then uses Open Firmware APIs to populate and probe
endpoint bus children.

> diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
> --- a/drivers/misc/Kconfig
> +++ b/drivers/misc/Kconfig
> @@ -568,6 +568,15 @@ config MCHP_LAN966X_PCI
>  	    - lan966x-miim (MDIO_MSCC_MIIM)
>  	    - lan966x-switch (LAN966X_SWITCH)
>  
> +config TC9564_PCI
> +	tristate "Toshiba TC9564 PCI function support"
> +	depends on PCI

[Severity: Medium]
Should this configuration also depend on OF and PCI_DYNAMIC_OF_NODES?

Because the driver relies entirely on Open Firmware to function, compiling
it without CONFIG_OF or CONFIG_PCI_DYNAMIC_OF_NODES will result in a
successful build but an unconditional runtime probe failure.

[ ... ]

> diff --git a/drivers/misc/tc9564-pci.c b/drivers/misc/tc9564-pci.c
> --- /dev/null
> +++ b/drivers/misc/tc9564-pci.c
> @@ -0,0 +1,84 @@
[ ... ]
> +static int
> +tc9564_function_probe(struct pci_dev *pdev, const struct pci_device_id *id)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct device_node *np;
> +	int ret;
> +
> +	/* Despite being a PCI device, we require devicetree */
> +	np = dev_of_node(dev);
> +	if (!np)
> +		return dev_err_probe(dev, -EINVAL, "no devicetree node\n");

[Severity: Medium]
Will this probe fail unconditionally if the required dependencies are missing?

If CONFIG_OF is disabled, dev_of_node() will always return NULL, causing
dev_err_probe() to trigger here.

Similarly, this commit relies on of_pci_make_dev_node() via a PCI quirk to
dynamically create the devicetree node for the PCIe function. If
CONFIG_PCI_DYNAMIC_OF_NODES is disabled, of_pci_make_dev_node() compiles
to an empty stub, meaning the node is never created.

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260915181003.1633543-1-elder@riscstar.com?part=2