From: Vladimir Oltean <olteanv@gmail.com>
To: "Russell King (Oracle)" <linux@armlinux.org.uk>
Cc: Martyn Welch <martyn.welch@collabora.com>,
Andrew Lunn <andrew@lunn.ch>,
Vivien Didelot <vivien.didelot@gmail.com>,
Florian Fainelli <f.fainelli@gmail.com>,
netdev@vger.kernel.org, kernel@collabora.com
Subject: Re: mv88e6240 configuration broken for B850v3
Date: Tue, 7 Dec 2021 16:37:05 +0200 [thread overview]
Message-ID: <20211207143705.46fd2zavniwb3gri@skbuf> (raw)
In-Reply-To: <Ya9op2QJwWRyqmDY@shell.armlinux.org.uk>
On Tue, Dec 07, 2021 at 01:59:03PM +0000, Russell King (Oracle) wrote:
> The change that I have proposed is based on two patches:
>
> 1) Change mv88e6xxx_port_ppu_updates() to behave sensibly for the 6250
> family of DSA switches.
>
> 2) Un-force the link-down in mv88e6xxx_mac_config()
>
> This gives us more consistency. The checks become:
>
> a) mac_link_down():
>
> if ((!mv88e6xxx_port_ppu_updates(chip, port) ||
> mode == MLO_AN_FIXED) && ops->port_sync_link)
> err = ops->port_sync_link(chip, port, mode, false);
>
> b) mac_link_up():
>
> if (!mv88e6xxx_port_ppu_updates(chip, port) ||
> mode == MLO_AN_FIXED) {
> ...
> if (ops->port_sync_link)
> err = ops->port_sync_link(chip, port, mode, true);
> }
>
> c) mac_config():
>
> if (chip->info->ops->port_set_link &&
> ((mode == MLO_AN_INBAND && p->interface != state->interface) ||
> (mode == MLO_AN_PHY && mv88e6xxx_port_ppu_updates(chip, port))))
> chip->info->ops->port_set_link(chip, port, LINK_UNFORCED);
>
> The "(mode == MLO_AN_INBAND && p->interface != state->interface)"
> expression comes from the existing code, so isn't something that
> needs discussion.
>
> We want to preserve the state of the link-force for MLO_AN_FIXED,
> so the only case for discussion is the new MLO_AN_PHY. It can be
> seen that all three methods above end up using the same decision,
> and essentially if mv88e6xxx_port_ppu_updates() is true, meaning
> there is a non-software method to handle the status updates, then
> we (a) don't do any forcing in the mac_link_*() methods and turn
> off the forcing in mac_config().
Ok, so if we are in:
- MLO_AN_PHY (internal or external) and PPU enabled, we're letting the link unforced in mac_config
- MLO_AN_PHY (internal or external) and PPU disabled, we're forcing the link up in mac_link_up,
via the "!mv88e6xxx_port_ppu_updates()" check.
- MLO_AN_FIXED, we're also forcing the link up in mac_link_up, via the
"mode == MLO_AN_FIXED" check.
So in Martyn's case, a CPU port internal PHY link which is forced down
in mac_link_down would either be forced up or unforced, but never be
left the way in which mac_link_down put it. That is good and appears
robust.
Although it isn't strictly true that "[ if ] there is a non-software
method to handle the status updates, then we don't do any forcing in
the mac_link_*() methods", because technically we still do in
mac_link_down, due to the " || mode == MLO_AN_FIXED" condition plus the
way in which we are called, it's just that we undo it later.
next prev parent reply other threads:[~2021-12-07 14:37 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-12-03 9:06 mv88e6240 configuration broken for B850v3 Martyn Welch
2021-12-03 16:25 ` Andrew Lunn
2021-12-06 17:44 ` Martyn Welch
2021-12-06 18:26 ` Martyn Welch
2021-12-06 18:31 ` Vladimir Oltean
2021-12-06 18:37 ` Martyn Welch
2021-12-06 18:50 ` Vladimir Oltean
2021-12-06 19:24 ` Martyn Welch
2021-12-06 19:37 ` Vladimir Oltean
2021-12-06 19:53 ` Andrew Lunn
2021-12-06 20:01 ` Vladimir Oltean
2021-12-06 20:18 ` Russell King (Oracle)
2021-12-06 20:29 ` Vladimir Oltean
2021-12-07 14:09 ` Andrew Lunn
2021-12-06 21:44 ` Vladimir Oltean
2021-12-06 22:13 ` Russell King (Oracle)
2021-12-06 20:07 ` Russell King (Oracle)
2021-12-06 20:23 ` Vladimir Oltean
2021-12-06 20:51 ` Russell King (Oracle)
2021-12-06 21:13 ` Vladimir Oltean
2021-12-06 21:27 ` Russell King (Oracle)
2021-12-06 21:49 ` Russell King (Oracle)
2021-12-06 23:27 ` Vladimir Oltean
2021-12-07 0:58 ` Russell King (Oracle)
2021-12-07 13:24 ` Vladimir Oltean
2021-12-07 13:59 ` Russell King (Oracle)
2021-12-07 14:37 ` Vladimir Oltean [this message]
2021-12-07 14:53 ` Russell King (Oracle)
2021-12-06 21:51 ` Vladimir Oltean
2021-12-06 22:17 ` Andrew Lunn
2021-12-06 22:22 ` Russell King (Oracle)
2021-12-06 23:44 ` Vladimir Oltean
2021-12-07 2:06 ` Andrew Lunn
2021-12-07 12:48 ` Vladimir Oltean
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20211207143705.46fd2zavniwb3gri@skbuf \
--to=olteanv@gmail.com \
--cc=andrew@lunn.ch \
--cc=f.fainelli@gmail.com \
--cc=kernel@collabora.com \
--cc=linux@armlinux.org.uk \
--cc=martyn.welch@collabora.com \
--cc=netdev@vger.kernel.org \
--cc=vivien.didelot@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).