Re: [PATCHv4 1/2] PCI: fu740: fix finding GPIOs

[Bjorn Helgaas]

On Mon, Feb 21, 2022 at 09:03:46PM +0000, Ben Dooks wrote:
> The calls to devm_gpiod_get_optional() have the -gpios at the end of
> the name but the GPIO core code is already adding the suffix during
> the lookup. This means the PCIe driver is not finding the necessary
> reset or power lines to allow initialisation of the PCIe.
> 
> This bug has not been noticed as if U-Boot has setup the GPIO lines
> for the hardware when it does the PCIe initialisation (either by
> booting from PCIe or user command to access PCIe) then the PCIe
> will work in Linux. The U-Boot as supplied by SiFive does not by
> default initialise any PCIe component.

Lorenzo, if you apply this, would you mind s/fix/Fix/ in the subject?
Or maybe even update to "Drop redundant '-gpios' from DT GPIO lookup"?

> Signed-off-by: Ben Dooks <ben.dooks@xxxxxxxxxxxxxxx>
> ---
>  drivers/pci/controller/dwc/pcie-fu740.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/pci/controller/dwc/pcie-fu740.c b/drivers/pci/controller/dwc/pcie-fu740.c
> index 00cde9a248b5..842b7202b96e 100644
> --- a/drivers/pci/controller/dwc/pcie-fu740.c
> +++ b/drivers/pci/controller/dwc/pcie-fu740.c
> @@ -259,11 +259,11 @@ static int fu740_pcie_probe(struct platform_device *pdev)
>  		return PTR_ERR(afp->mgmt_base);
>  
>  	/* Fetch GPIOs */
> -	afp->reset = devm_gpiod_get_optional(dev, "reset-gpios", GPIOD_OUT_LOW);
> +	afp->reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);
>  	if (IS_ERR(afp->reset))
>  		return dev_err_probe(dev, PTR_ERR(afp->reset), "unable to get reset-gpios\n");
>  
> -	afp->pwren = devm_gpiod_get_optional(dev, "pwren-gpios", GPIOD_OUT_LOW);
> +	afp->pwren = devm_gpiod_get_optional(dev, "pwren", GPIOD_OUT_LOW);
>  	if (IS_ERR(afp->pwren))
>  		return dev_err_probe(dev, PTR_ERR(afp->pwren), "unable to get pwren-gpios\n");
>  
> -- 
> 2.34.1
>