Re: [PATCH 2/2] net: dsa: b53: mdio: add support for BCM53134

["Álvaro Fernández Rojas" <noltari@gmail.com>]

El vie, 24 mar 2023 a las 9:29, Paul Geurts
(<paul.geurts@prodrive-technologies.com>) escribió:
>
> > -----Original Message-----
> > From: Álvaro Fernández Rojas <noltari@gmail.com>
> > Sent: donderdag 23 maart 2023 23:13
> > To: Florian Fainelli <f.fainelli@gmail.com>
> > Cc: Paul Geurts <paul.geurts@prodrive-technologies.com>;
> > jonas.gorski@gmail.com; andrew@lunn.ch; olteanv@gmail.com;
> > davem@davemloft.net; edumazet@google.com; kuba@kernel.org;
> > pabeni@redhat.com; robh+dt@kernel.org;
> > krzysztof.kozlowski+dt@linaro.org; netdev@vger.kernel.org;
> > devicetree@vger.kernel.org; linux-kernel@vger.kernel.org
> > Subject: Re: [PATCH 2/2] net: dsa: b53: mdio: add support for BCM53134
> >
> > El jue, 23 mar 2023 a las 22:02, Florian Fainelli
> > (<f.fainelli@gmail.com>) escribió:
> > >
> > > On 3/23/23 13:10, Paul Geurts wrote:
> > > >> -----Original Message-----
> > > >> From: Florian Fainelli <f.fainelli@gmail.com>
> > > >> Sent: donderdag 23 maart 2023 17:43
> > > >> To: Álvaro Fernández Rojas <noltari@gmail.com>; Paul Geurts
> > > >> <paul.geurts@prodrive-technologies.com>; jonas.gorski@gmail.com;
> > > >> andrew@lunn.ch; olteanv@gmail.com; davem@davemloft.net;
> > > >> edumazet@google.com; kuba@kernel.org; pabeni@redhat.com;
> > > >> robh+dt@kernel.org; krzysztof.kozlowski+dt@linaro.org;
> > > >> netdev@vger.kernel.org; devicetree@vger.kernel.org; linux-
> > > >> kernel@vger.kernel.org
> > > >> Subject: Re: [PATCH 2/2] net: dsa: b53: mdio: add support for
> > > >> BCM53134
> > > >>
> > > >> On 3/23/23 05:18, Álvaro Fernández Rojas wrote:
> > > >>> From: Paul Geurts <paul.geurts@prodrive-technologies.com>
> > > >>>
> > > >>> Add support for the BCM53134 Ethernet switch in the existing b53
> > > >>> dsa
> > > >> driver.
> > > >>> BCM53134 is very similar to the BCM58XX series.
> > > >>>
> > > >>> Signed-off-by: Paul Geurts <paul.geurts@prodrive-technologies.com>
> > > >>> Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
> > > >>> ---
> > > >>>    drivers/net/dsa/b53/b53_common.c | 53
> > > >> +++++++++++++++++++++++++++++++-
> > > >>>    drivers/net/dsa/b53/b53_mdio.c   |  5 ++-
> > > >>>    drivers/net/dsa/b53/b53_priv.h   |  9 +++++-
> > > >>>    3 files changed, 64 insertions(+), 3 deletions(-)
> > > >>>
> > > >>> diff --git a/drivers/net/dsa/b53/b53_common.c
> > > >>> b/drivers/net/dsa/b53/b53_common.c
> > > >>> index 1f9b251a5452..aaa0813e6f59 100644
> > > >>> --- a/drivers/net/dsa/b53/b53_common.c
> > > >>> +++ b/drivers/net/dsa/b53/b53_common.c
> > > >>> @@ -1282,6 +1282,42 @@ static void b53_adjust_link(struct
> > > >>> dsa_switch
> > > >> *ds, int port,
> > > >>>     if (is63xx(dev) && port >= B53_63XX_RGMII0)
> > > >>>             b53_adjust_63xx_rgmii(ds, port, phydev->interface);
> > > >>>
> > > >>> +   if (is53134(dev) && phy_interface_is_rgmii(phydev)) {
> > > >>
> > > >> Why is not this in the same code block as the one for the is531x5()
> > > >> device like
> > > >> this:
> > > >>
> > > >> diff --git a/drivers/net/dsa/b53/b53_common.c
> > > >> b/drivers/net/dsa/b53/b53_common.c
> > > >> index 59cdfc51ce06..1c64b6ce7e78 100644
> > > >> --- a/drivers/net/dsa/b53/b53_common.c
> > > >> +++ b/drivers/net/dsa/b53/b53_common.c
> > > >> @@ -1235,7 +1235,7 @@ static void b53_adjust_link(struct dsa_switch
> > > >> *ds, int port,
> > > >>                                 tx_pause, rx_pause);
> > > >>           b53_force_link(dev, port, phydev->link);
> > > >>
> > > >> -       if (is531x5(dev) && phy_interface_is_rgmii(phydev)) {
> > > >> +       if ((is531x5(dev) || is53134(dev)) &&
> > > >> phy_interface_is_rgmii(phydev)) {
> > > >>                   if (port == dev->imp_port)
> > > >>                           off = B53_RGMII_CTRL_IMP;
> > > >>                   else
> > > >>
> > > >> Other than that, LGTM!
> > > >> --
> > > >> Florian
> > > >
> > > > I think the only reason is that the BCM53134 does not support the
> > > > RGMII_CTRL_TIMING_SEL bit, which is set in the original block. I
> > > > agree Putting a if statement around rgmii_ctrl |=
> > > > RGMII_CTRL_TIMING_SEL; would prevent a lot of code duplication.
> > > > _however_, after looking at it again, I don’t think the device does
> > > > not support the bit. When looking at the datasheet, The same bit in
> > > > the this register is called BYPASS_2NS_DEL. It's very uncommon For
> > > > Broadcom to make such a change in the register interface, so maybe
> > > > they Just renamed it. Do you think this could be the same bit?
> > >
> > > Yes, I think this is exactly the same bit, just named differently.
> > > What strikes me as odd is that neither of the 53115, 53125 or 53128
> > > which are guarded by the is531x5() conditional have it defined.
> >
> > If this is true then we can safely add 53134 to is531x5() conditional and reuse
> > the existing code.
> >
> > > --
> > > Florian
> > >
> >
> > --
> > Álvaro
>
> With the bit set on my device, everything keeps working just fine. I indeed think
> This is just the same bit. I have requested some clarity from our FAE at
> Broadcom. We could wait for their answer (which could take a while), or just
> assume setting this bit is fine an push the patches. I'll leave that up to you.

I've checked and mine works fine too, so I simplified the patch in v2.

>
> ---
> Paul

--
Álvaro