From: "Pali Rohár" <pali@kernel.org>
To: Andrew Lunn <andrew@lunn.ch>
Cc: "Vivien Didelot" <vivien.didelot@gmail.com>,
"Florian Fainelli" <f.fainelli@gmail.com>,
"Vladimir Oltean" <olteanv@gmail.com>,
"David S. Miller" <davem@davemloft.net>,
"Jakub Kicinski" <kuba@kernel.org>,
"Marek Behún" <kabel@kernel.org>,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] net: phy: marvell: fix detection of PHY on Topaz switches
Date: Mon, 12 Apr 2021 15:34:47 +0200 [thread overview]
Message-ID: <20210412133447.fyqkavrs5r5wbino@pali> (raw)
In-Reply-To: <YHRH2zWsYkv/yjYz@lunn.ch>
On Monday 12 April 2021 15:15:07 Andrew Lunn wrote:
> > +static u16 mv88e6xxx_physid_for_family(enum mv88e6xxx_family family);
> > +
>
> No forward declaration please. Move the code around. It is often best
> to do that in a patch which just moves code, no other changes. It
> makes it easier to review.
Avoiding forward declaration would mean to move about half of source
code. mv88e6xxx_physid_for_family depends on mv88e6xxx_table which
depends on all _ops structures which depends on all lot of other
functions.
I wanted to create a small fixup patch which can be easily backported to
stable releases which are affected by this issue.
If you do not like forward declarations, I can create a followup patch
which moves this half of code in this file to avoid forward declaration.
But having it in one patch would mean to complicate reviewing code...
> > static int mv88e6xxx_mdio_read(struct mii_bus *bus, int phy, int reg)
> > {
> > struct mv88e6xxx_mdio_bus *mdio_bus = bus->priv;
> > @@ -3040,24 +3042,9 @@ static int mv88e6xxx_mdio_read(struct mii_bus *bus, int phy, int reg)
> > err = chip->info->ops->phy_read(chip, bus, phy, reg, &val);
> > mv88e6xxx_reg_unlock(chip);
> >
> > - if (reg == MII_PHYSID2) {
> > - /* Some internal PHYs don't have a model number. */
> > - if (chip->info->family != MV88E6XXX_FAMILY_6165)
> > - /* Then there is the 6165 family. It gets is
> > - * PHYs correct. But it can also have two
> > - * SERDES interfaces in the PHY address
> > - * space. And these don't have a model
> > - * number. But they are not PHYs, so we don't
> > - * want to give them something a PHY driver
> > - * will recognise.
> > - *
> > - * Use the mv88e6390 family model number
> > - * instead, for anything which really could be
> > - * a PHY,
> > - */
> > - if (!(val & 0x3f0))
> > - val |= MV88E6XXX_PORT_SWITCH_ID_PROD_6390 >> 4;
> > - }
> > + /* Some internal PHYs don't have a model number. */
> > + if (reg == MII_PHYSID2 && !(val & 0x3f0))
> > + val |= mv88e6xxx_physid_for_family(chip->info->family);
> >
> > return err ? err : val;
> > }
> > @@ -5244,6 +5231,39 @@ static const struct mv88e6xxx_info *mv88e6xxx_lookup_info(unsigned int prod_num)
> > return NULL;
> > }
> >
> > +/* This table contains representative model for every family */
> > +static const enum mv88e6xxx_model family_model_table[] = {
> > + [MV88E6XXX_FAMILY_6095] = MV88E6095,
> > + [MV88E6XXX_FAMILY_6097] = MV88E6097,
> > + [MV88E6XXX_FAMILY_6185] = MV88E6185,
> > + [MV88E6XXX_FAMILY_6250] = MV88E6250,
> > + [MV88E6XXX_FAMILY_6320] = MV88E6320,
> > + [MV88E6XXX_FAMILY_6341] = MV88E6341,
> > + [MV88E6XXX_FAMILY_6351] = MV88E6351,
> > + [MV88E6XXX_FAMILY_6352] = MV88E6352,
> > + [MV88E6XXX_FAMILY_6390] = MV88E6390,
> > +};
>
> This table is wrong. MV88E6390 does not equal
> MV88E6XXX_PORT_SWITCH_ID_PROD_6390. MV88E6XXX_PORT_SWITCH_ID_PROD_6390
> was chosen because it is already an MDIO device ID, in register 2 and
> 3. It probably will never clash with a real Marvell PHY ID. MV88E6390
> is just a small integer, and there is a danger it will clash with a
> real PHY.
So... how to solve this issue? What should be in the mapping table?
> > --- a/drivers/net/phy/marvell.c
> > +++ b/drivers/net/phy/marvell.c
> > @@ -3021,9 +3021,34 @@ static struct phy_driver marvell_drivers[] = {
> > .get_stats = marvell_get_stats,
> > },
> > {
> > - .phy_id = MARVELL_PHY_ID_88E6390,
> > + .phy_id = MARVELL_PHY_ID_88E6341_FAMILY,
> > .phy_id_mask = MARVELL_PHY_ID_MASK,
> > - .name = "Marvell 88E6390",
> > + .name = "Marvell 88E6341 Family",
>
> You cannot just replace the MARVELL_PHY_ID_88E6390. That will break
> the 6390! You need to add the new PHY for the 88E6341.
I have not replaced anything. I just put there a new phy_id section for
88E6341. You are probably confused by 'git diff' output as quickly
looking at it, somebody can think that there is phy replacement. But
there is no replacement, I only added a new PHY. Entry for 88E6390 is
still there!
Also this is reason why I wanted to avoid big code movement. It will be
harder to read the 'git diff' output in this patch.
next prev parent reply other threads:[~2021-04-12 13:34 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-12 12:14 [PATCH] net: phy: marvell: fix detection of PHY on Topaz switches Pali Rohár
2021-04-12 13:15 ` Andrew Lunn
2021-04-12 13:34 ` Pali Rohár [this message]
2021-04-12 14:30 ` Andrew Lunn
2021-04-12 14:39 ` Pali Rohár
2021-04-12 14:44 ` Andrew Lunn
2021-04-12 15:01 ` Pali Rohár
2021-04-12 15:32 ` Andrew Lunn
2021-04-12 15:52 ` Pali Rohár
2021-04-12 16:12 ` Andrew Lunn
2021-04-12 16:38 ` Pali Rohár
2021-04-12 23:45 ` Marek Behún
2021-04-12 16:57 ` [PATCH v2] " Pali Rohár
2021-04-12 17:44 ` Andrew Lunn
2021-04-12 21:30 ` patchwork-bot+netdevbpf
2021-04-12 23:25 ` Marek Behún
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