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From:   Chris Healy <cphealy@gmail.com>
Date:   Mon, 6 Jul 2020 16:04:50 -0700
Message-ID: <CAFXsbZptqExMHK0BcDqO-Fdu6qs6hD2toWgNprfAeq6YXWSmLA@mail.gmail.com>
Subject: Re: [PATCH] net: sfp: Unique GPIO interrupt names
To:     Russell King - ARM Linux admin <linux@armlinux.org.uk>
Cc:     Andrew Lunn <andrew@lunn.ch>,
        Florian Fainelli <f.fainelli@gmail.com>,
        Heiner Kallweit <hkallweit1@gmail.com>,
        "David S. Miller" <davem@davemloft.net>, kuba@kernel.org,
        netdev <netdev@vger.kernel.org>,
        linux-kernel <linux-kernel@vger.kernel.org>
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On Mon, Jul 6, 2020 at 1:42 PM Russell King - ARM Linux admin
<linux@armlinux.org.uk> wrote:
>
> On Mon, Jul 06, 2020 at 12:38:37PM -0700, Chris Healy wrote:
> > Dynamically generate a unique GPIO interrupt name, based on the
> > device name and the GPIO name.  For example:
> >
> > 103:          0   sx1503q  12 Edge      sff2-los
> > 104:          0   sx1503q  13 Edge      sff3-los
> >
> > The sffX indicates the SFP the loss of signal GPIO is associated with.
> >
> > Signed-off-by: Chris Healy <cphealy@gmail.com>
>
> This doesn't work in all cases.
>
> > ---
> >  drivers/net/phy/sfp.c | 6 +++++-
> >  1 file changed, 5 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/net/phy/sfp.c b/drivers/net/phy/sfp.c
> > index 73c2969f11a4..9b03c7229320 100644
> > --- a/drivers/net/phy/sfp.c
> > +++ b/drivers/net/phy/sfp.c
> > @@ -220,6 +220,7 @@ struct sfp {
> >      struct phy_device *mod_phy;
> >      const struct sff_data *type;
> >      u32 max_power_mW;
> > +    char sfp_irq_name[32];
> >
> >      unsigned int (*get_state)(struct sfp *);
> >      void (*set_state)(struct sfp *, unsigned int);
> > @@ -2349,12 +2350,15 @@ static int sfp_probe(struct platform_device *pdev)
> >              continue;
> >          }
> >
> > +        snprintf(sfp->sfp_irq_name, sizeof(sfp->sfp_irq_name),
> > +             "%s-%s", dev_name(sfp->dev), gpio_of_names[i]);
>
> sfp_irq_name will be overwritten for each GPIO IRQ claimed, which means
> all IRQs for a particular cage will end up with the same name.
> sfp_irq_name[] therefore needs to be an array of names, one per input.

Good point.  I'll add the necessary support to deal with this case and
test on my side with a hacked up devicetree file providing some
additional GPIOs and include this in the next version of the patch.

>
> Thanks.
>
> --
> RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
> FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!