From: Bjorn Helgaas <helgaas@kernel.org>
To: Ben Dooks <ben.dooks@codethink.co.uk>
Cc: paul.walmsley@sifive.com, greentime.hu@sifive.com,
lorenzo.pieralisi@arm.com, robh@kernel.org, kw@linux.com,
bhelgaas@google.com, linux-pci@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org
Subject: Re: [PATCHv4 1/2] PCI: fu740: fix finding GPIOs
Date: Wed, 23 Feb 2022 14:51:29 -0600 [thread overview]
Message-ID: <20220223205129.GA148800@bhelgaas> (raw)
In-Reply-To: <20220221210347.1335004-1-ben.dooks@codethink.co.uk>
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@codethink.co.uk>
> ---
> 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
>
prev parent reply other threads:[~2022-02-23 20:51 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-21 21:03 [PATCHv4 1/2] PCI: fu740: fix finding GPIOs Ben Dooks
2022-02-21 21:03 ` [PATCHv4 2/2] PCI: fu740: Force gen1 for initial device probe Ben Dooks
2022-02-23 20:51 ` Bjorn Helgaas
2022-02-23 21:19 ` Maciej W. Rozycki
2022-02-28 23:15 ` Ben Dooks
2022-02-28 17:45 ` Ben Dooks
2022-02-23 20:51 ` Bjorn Helgaas [this message]
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