netdev - Re: [PATCH net] net: mvpp2: let phylink manage the carrier state

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Date:   Mon, 17 Sep 2018 07:57:40 -0700 (PDT)
From:   David Miller <davem@...emloft.net>
To:     antoine.tenart@...tlin.com
Cc:     linux@...linux.org.uk, netdev@...r.kernel.org,
        linux-kernel@...r.kernel.org, thomas.petazzoni@...tlin.com,
        maxime.chevallier@...tlin.com, gregory.clement@...tlin.com,
        miquel.raynal@...tlin.com, nadavh@...vell.com, stefanc@...vell.com,
        ymarkman@...vell.com, mw@...ihalf.com
Subject: Re: [PATCH net] net: mvpp2: let phylink manage the carrier state

From: Antoine Tenart <antoine.tenart@...tlin.com>
Date: Fri, 14 Sep 2018 16:56:35 +0200

> Net drivers using phylink shouldn't mess with the link carrier
> themselves and should let phylink manage it. The mvpp2 driver wasn't
> following this best practice as the mac_config() function made calls to
> change the link carrier state. This led to wrongly reported carrier link
> state which then triggered other issues. This patch fixes this
> behaviour.
> 
> But the PPv2 driver relied on this misbehaviour in two cases: for fixed
> links and when not using phylink (ACPI mode). The later was fixed by
> adding an explicit call to link_up(), which when the ACPI mode will use
> phylink should be removed.
> 
> The fixed link case was relying on the mac_config() function to set the
> link up, as we found an issue in phylink_start() which assumes the
> carrier is off. If not, the link_up() function is never called. To fix
> this, a call to netif_carrier_off() is added just before phylink_start()
> so that we do not introduce a regression in the driver.
> 
> Fixes: 4bb043262878 ("net: mvpp2: phylink support")
> Reported-by: Russell King <linux@...linux.org.uk>
> Signed-off-by: Antoine Tenart <antoine.tenart@...tlin.com>

Applied.