Re: [PATCH] PCI: kirin: Return -EPROBE_DEFER in case the gpio isn't ready

From: Lorenzo Pieralisi
Date: Mon Sep 21 2020 - 07:22:18 EST


On Fri, Sep 18, 2020 at 02:38:00PM +0200, Bean Huo wrote:
> From: Bean Huo <beanhuo@xxxxxxxxxx>
>
> PCI driver might be probed before the gpiochip, so, of_get_named_gpio()
> can return -EPROBE_DEFER. And let kirin_pcie_probe() directly return
> -ENODEV, which will result in the PCIe probe failure and the PCIe
> will not be probed again after the gpiochip driver is loaded.
>
> Fix the above issue by letting kirin_pcie_probe() return -EPROBE_DEFER in
> such a case.
>
> Fixes: 6e0832fa432e ("PCI: Collect all native drivers under drivers/pci/controller")

This is certainly not the commit that triggered the issue so I would
remove it. Kirin maintainers are CC'ed, waiting for their ACK.

Lorenzo

> Signed-off-by: Bean Huo <beanhuo@xxxxxxxxxx>
> ---
> drivers/pci/controller/dwc/pcie-kirin.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/pci/controller/dwc/pcie-kirin.c b/drivers/pci/controller/dwc/pcie-kirin.c
> index e496f51e0152..74b88d158072 100644
> --- a/drivers/pci/controller/dwc/pcie-kirin.c
> +++ b/drivers/pci/controller/dwc/pcie-kirin.c
> @@ -507,8 +507,12 @@ static int kirin_pcie_probe(struct platform_device *pdev)
>
> kirin_pcie->gpio_id_reset = of_get_named_gpio(dev->of_node,
> "reset-gpios", 0);
> - if (kirin_pcie->gpio_id_reset < 0)
> + if (kirin_pcie->gpio_id_reset == -EPROBE_DEFER) {
> + return -EPROBE_DEFER;
> + } else if (!gpio_is_valid(kirin_pcie->gpio_id_reset)) {
> + dev_err(dev, "unable to get a valid gpio pin\n");
> return -ENODEV;
> + }
>
> ret = kirin_pcie_power_on(kirin_pcie);
> if (ret)
> --
> 2.17.1
>