Re: [PATCH v2 1/4] PCI: rockchip: Make 'ep-gpios' DT property optional

From: Rob Herring <robh@kernel.org>
To: Chen-Yu Tsai <wens@kernel.org>
Cc: Shawn Lin <shawn.lin@rock-chips.com>,
	Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
	Bjorn Helgaas <bhelgaas@google.com>,
	Heiko Stuebner <heiko@sntech.de>,
	Robin Murphy <robin.murphy@arm.com>,
	Johan Jonker <jbx6244@gmail.com>, PCI <linux-pci@vger.kernel.org>,
	"open list:ARM/Rockchip SoC..."
	<linux-rockchip@lists.infradead.org>,
	linux-arm-kernel <linux-arm-kernel@lists.infradead.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	devicetree <devicetree@vger.kernel.org>
Subject: Re: [PATCH v2 1/4] PCI: rockchip: Make 'ep-gpios' DT property optional
Date: Mon, 14 Dec 2020 08:17:15 -0600	[thread overview]
Message-ID: <CAL_Jsq+0fMQkqYZ0W0eqnB+J016n-VnBm0TM2Hv1nqhO8_yUbQ@mail.gmail.com> (raw)
In-Reply-To: <CAGb2v6409SeptNUvMnpozriZ-L7iFCFFoG+=fJrtohxezDrEDQ@mail.gmail.com>

On Sat, Dec 12, 2020 at 9:18 AM Chen-Yu Tsai <wens@kernel.org> wrote:
>
> On Mon, Dec 7, 2020 at 10:11 PM Rob Herring <robh@kernel.org> wrote:
> >
> > On Wed, Nov 18, 2020 at 1:17 AM Chen-Yu Tsai <wens@kernel.org> wrote:
> > >
> > > From: Chen-Yu Tsai <wens@csie.org>
> > >
> > > The Rockchip PCIe controller DT binding clearly states that 'ep-gpios' is
> > > an optional property. And indeed there are boards that don't require it.
> > >
> > > Make the driver follow the binding by using devm_gpiod_get_optional()
> > > instead of devm_gpiod_get().
> > >
> > > Fixes: e77f847df54c ("PCI: rockchip: Add Rockchip PCIe controller support")
> > > Fixes: 956cd99b35a8 ("PCI: rockchip: Separate common code from RC driver")
> > > Fixes: 964bac9455be ("PCI: rockchip: Split out rockchip_pcie_parse_dt() to parse DT")
> > > Signed-off-by: Chen-Yu Tsai <wens@csie.org>
> > > ---
> > > Changes since v1:
> > >
> > >   - Rewrite subject to match existing convention and reference
> > >     'ep-gpios' DT property instead of the 'ep_gpio' field
> > > ---
> > >  drivers/pci/controller/pcie-rockchip.c | 2 +-
> > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > >
> > > diff --git a/drivers/pci/controller/pcie-rockchip.c b/drivers/pci/controller/pcie-rockchip.c
> > > index 904dec0d3a88..c95950e9004f 100644
> > > --- a/drivers/pci/controller/pcie-rockchip.c
> > > +++ b/drivers/pci/controller/pcie-rockchip.c
> > > @@ -118,7 +118,7 @@ int rockchip_pcie_parse_dt(struct rockchip_pcie *rockchip)
> > >         }
> > >
> > >         if (rockchip->is_rc) {
> > > -               rockchip->ep_gpio = devm_gpiod_get(dev, "ep", GPIOD_OUT_HIGH);
> > > +               rockchip->ep_gpio = devm_gpiod_get_optional(dev, "ep", GPIOD_OUT_HIGH);
> > >                 if (IS_ERR(rockchip->ep_gpio)) {
> > >                         dev_err(dev, "missing ep-gpios property in node\n");
> >
> > You should drop the error message. What it says is now never the
> > reason for the error and it could most likely be a deferred probe
> > which you don't want an error message for.
>
> What about switching to dev_err_probe() instead?
>
> That way deferred probe errors get silenced (or get a better debug message),
> and error messages for other issues, such as miswritten gpio properties are
> still produced.

I guess, but those errors should be in the subsystem code IMO rather
than every driver.

Rob