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 <25fbf4763c28af4c73162dec254af6111e05461b.camel@pengutronix.de>
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From:   Peter Geis <pgwipeout@gmail.com>
Date:   Tue, 26 Apr 2022 08:17:26 -0400
Message-ID: <CAMdYzYpw-vUFTM=pmnASNrWvi0X4mM0hFKX7TRLHhJyehfuHkw@mail.gmail.com>
Subject: Re: [PATCH v8 2/5] PCI: dwc: rockchip: reset core at driver probe
To:     Philipp Zabel <p.zabel@pengutronix.de>
Cc:     Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
        Rob Herring <robh@kernel.org>,
        =?UTF-8?Q?Krzysztof_Wilczy=C5=84ski?= <kw@linux.com>,
        Bjorn Helgaas <bhelgaas@google.com>,
        Heiko Stuebner <heiko@sntech.de>,
        "open list:ARM/Rockchip SoC..." <linux-rockchip@lists.infradead.org>,
        Marc Zyngier <maz@kernel.org>, PCI <linux-pci@vger.kernel.org>,
        devicetree <devicetree@vger.kernel.org>,
        arm-mail-list <linux-arm-kernel@lists.infradead.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
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On Mon, Apr 25, 2022 at 5:20 AM Philipp Zabel <p.zabel@pengutronix.de> wrote:
>
> Hi Peter,
>
> On Sa, 2022-04-23 at 11:24 -0400, Peter Geis wrote:
> > The PCIe controller is in an unknown state at driver probe. This can
> > lead to undesireable effects when the driver attempts to configure the
> > controller.
> >
> > Prevent issues in the future by resetting the core during probe.
> >
> > Signed-off-by: Peter Geis <pgwipeout@gmail.com>
> > ---
> >  drivers/pci/controller/dwc/pcie-dw-rockchip.c | 22 +++++++------------
> >  1 file changed, 8 insertions(+), 14 deletions(-)
> >
> > diff --git a/drivers/pci/controller/dwc/pcie-dw-rockchip.c b/drivers/pci/controller/dwc/pcie-dw-rockchip.c
> > index c9b341e55cbb..d67ed811e752 100644
> > --- a/drivers/pci/controller/dwc/pcie-dw-rockchip.c
> > +++ b/drivers/pci/controller/dwc/pcie-dw-rockchip.c
> > @@ -152,7 +152,13 @@ static int rockchip_pcie_resource_get(struct platform_device *pdev,
> >       if (IS_ERR(rockchip->rst_gpio))
> >               return PTR_ERR(rockchip->rst_gpio);
> >
> > -     return 0;
> > +     rockchip->rst = devm_reset_control_array_get_exclusive(&pdev->dev);
> > +     if (IS_ERR(rockchip->rst))
> > +             return dev_err_probe(&pdev->dev, PTR_ERR(rockchip->rst),
> > +                                  "failed to get reset lines\n");
> > +
> > +     return reset_control_assert(rockchip->rst);
>
> This makes "rockchip_pcie_resource_get" a bit of a misnomer, maybe move
> this out into rockchip_pcie_probe()?

Ah, yes that does make sense, thanks.

>
> > +
>
> Superfluous whitespace.
>
> regards
> Philipp
>