Re: [PATCH net] net: broadcom: Imply BROADCOM_PHY for BCMGENET

From: Geert Uytterhoeven <geert@linux-m68k.org>
To: Florian Fainelli <f.fainelli@gmail.com>
Cc: netdev <netdev@vger.kernel.org>,
	Nicolas Saenz Julienne <nsaenzjulienne@suse.de>,
	Stefan Wahren <wahrenst@gmx.net>,
	Marek Szyprowski <m.szyprowski@samsung.com>,
	"David S. Miller" <davem@davemloft.net>,
	Thomas Gleixner <tglx@linutronix.de>,
	Tal Gilboa <talgi@mellanox.com>,
	Michael Chan <michael.chan@broadcom.com>,
	Andy Gospodarek <gospo@broadcom.com>,
	Randy Dunlap <rdunlap@infradead.org>,
	open list <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH net] net: broadcom: Imply BROADCOM_PHY for BCMGENET
Date: Sun, 10 May 2020 12:02:18 +0200	[thread overview]
Message-ID: <CAMuHMdVKAjh1TyNOFdNP_zXy8RNU8kD-Saoqha+wjcrR0v5YvQ@mail.gmail.com> (raw)
In-Reply-To: <ebac4532-6dae-5609-9629-ba10197671c3@gmail.com>

Hi Florian,

On Sat, May 9, 2020 at 7:12 PM Florian Fainelli <f.fainelli@gmail.com> wrote:
> On 5/9/2020 12:38 AM, Geert Uytterhoeven wrote:
> > On Sat, May 9, 2020 at 12:32 AM Florian Fainelli <f.fainelli@gmail.com> wrote:
> >> The GENET controller on the Raspberry Pi 4 (2711) is typically
> >> interfaced with an external Broadcom PHY via a RGMII electrical
> >> interface. To make sure that delays are properly configured at the PHY
> >> side, ensure that we get a chance to have the dedicated Broadcom PHY
> >> driver (CONFIG_BROADCOM_PHY) enabled for this to happen.
> >
> > I guess it can be interfaced to a different external PHY, too?
>
> Yes, although this has not happened yet to the best of my knowledge.
>
> >
> >> Fixes: 402482a6a78e ("net: bcmgenet: Clear ID_MODE_DIS in EXT_RGMII_OOB_CTRL when not needed")
> >> Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
> >> Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
> >
> >> --- a/drivers/net/ethernet/broadcom/Kconfig
> >> +++ b/drivers/net/ethernet/broadcom/Kconfig
> >> @@ -69,6 +69,7 @@ config BCMGENET
> >>          select BCM7XXX_PHY
> >>          select MDIO_BCM_UNIMAC
> >>          select DIMLIB
> >> +       imply BROADCOM_PHY if ARCH_BCM2835
> >
> > Which means support for the BROADCOM_PHY is always included
> > on ARCH_BCM2835, even if a different PHY is used?
>
> It is included by default on  and can be deselected if needed, which is
> exactly what we want here, a sane default, but without the inflexibility
> of "select".

I stand corrected: I can confirm the "imply" no longer selects the target
symbol, but merely changes the default.

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds