Re: [PATCH] PCI: kirin: Fix kirin960-pcie probe failure issue

Bjorn Helgaas
2022-02-02T21:40:31Z

On Wed, Feb 02, 2022 at 10:26:59AM -0600, Bjorn Helgaas wrote:
> [+cc Fan]
>
> If you're fixing a previous commit, please cc the author of that
> commit.
>
> I'd prefer the patch below because it avoids the casts of .data and
> the of_device_get_match_data() result, it doesn't silently default to
> PCIE_KIRIN_INTERNAL_PHY if a device without a .data is added, and it's
> the most common design pattern in drivers/pci/.
>
> What do you think?
> ...

> commit 3e21687be135 ("PCI: kirin: Add dev struct for of_device_get_match_data()")
> Author: Bjorn Helgaas <bhelgaas@google.com>
> Date: Wed Feb 2 09:52:41 2022 -0600
>
> PCI: kirin: Add dev struct for of_device_get_match_data()
>
> a622435fbe1a ("PCI: kirin: Prefer of_device_get_match_data()") broke
> kirin_pcie_probe() because it assumed match data of 0 was a failure when in
> fact, it meant the match data was "(void *)PCIE_KIRIN_INTERNAL_PHY".
>
> Therefore, probing of "hisilicon,kirin960-pcie" devices failed with -EINVAL
> and an "OF data missing" message.
>
> Add a struct kirin_pcie_data to encode the PHY type. Then the result of
> of_device_get_match_data() should always be a non-NULL pointer to a struct
> kirin_pcie_data that contains the PHY type.
>
> Fixes: a622435fbe1a ("PCI: kirin: Prefer of_device_get_match_data()")
> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

I applied this (with the obvious syntax fixes) to for-linus for v5.17.

> diff --git a/drivers/pci/controller/dwc/pcie-kirin.c b/drivers/pci/controller/dwc/pcie-kirin.c
> index fa6886d66488..0dc4e3395b37 100644
> --- a/drivers/pci/controller/dwc/pcie-kirin.c
> +++ b/drivers/pci/controller/dwc/pcie-kirin.c
> @@ -756,21 +756,27 @@ static int __exit kirin_pcie_remove(struct platform_device *pdev)
> return 0;
> }
>
> +struct kirin_pcie_data {
> + enum pcie_kirin_phy_type phy_type;
> +};
> +
> +static const struct kirin_pcie_data kirin_960_data = {
> + .phy_type = PCIE_KIRIN_INTERNAL_PHY;
> +};
> +
> +static const struct kirin_pcie_data kirin_970_data = {
> + .phy_type = PCIE_KIRIN_EXTERNAL_PHY;
> +};
> +
> static const struct of_device_id kirin_pcie_match[] = {
> - {
> - .compatible = "hisilicon,kirin960-pcie",
> - .data = (void *)PCIE_KIRIN_INTERNAL_PHY
> - },
> - {
> - .compatible = "hisilicon,kirin970-pcie",
> - .data = (void *)PCIE_KIRIN_EXTERNAL_PHY
> - },
> + { .compatible = "hisilicon,kirin960-pcie", .data = &kirin_960_data },
> + { .compatible = "hisilicon,kirin970-pcie", .data = &kirin_970_data },
> {},
> };
>
> static int kirin_pcie_probe(struct platform_device *pdev)
> {
> - enum pcie_kirin_phy_type phy_type;
> + struct kirin_pcie_data *data;
> struct device *dev = &pdev->dev;
> struct kirin_pcie *kirin_pcie;
> struct dw_pcie *pci;
> @@ -781,13 +787,12 @@ static int kirin_pcie_probe(struct platform_device *pdev)
> return -EINVAL;
> }
>
> - phy_type = (long)of_device_get_match_data(dev);
> - if (!phy_type) {
> + data = of_device_get_match_data(dev);
> + if (!data) {
> dev_err(dev, "OF data missing\n");
> return -EINVAL;
> }
>
> -
> kirin_pcie = devm_kzalloc(dev, sizeof(struct kirin_pcie), GFP_KERNEL);
> if (!kirin_pcie)
> return -ENOMEM;
> @@ -800,7 +805,7 @@ static int kirin_pcie_probe(struct platform_device *pdev)
> pci->ops = &kirin_dw_pcie_ops;
> pci->pp.ops = &kirin_pcie_host_ops;
> kirin_pcie->pci = pci;
> - kirin_pcie->type = phy_type;
> + kirin_pcie->type = data->phy_type;
>
> ret = kirin_pcie_get_resource(kirin_pcie, pdev);
> if (ret)