netdev - Re: [PATCH net-next] net: dsa: mv88e6xxx: debug ATU Age Time

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

Message-ID: <87inncj71i.fsf@weeman.i-did-not-set--mail-host-address--so-tickle-me>
Date:   Tue, 14 Mar 2017 09:56:41 -0400
From:   Vivien Didelot <vivien.didelot@...oirfairelinux.com>
To:     Andrew Lunn <andrew@...n.ch>,
        Matthias May <matthias.may@...atec.com>
Cc:     Florian Fainelli <f.fainelli@...il.com>, netdev@...r.kernel.org,
        linux-kernel@...r.kernel.org, kernel@...oirfairelinux.com,
        "David S. Miller" <davem@...emloft.net>,
        Jason Cobham <jcobham@...stertangent.com>
Subject: Re: [PATCH net-next] net: dsa: mv88e6xxx: debug ATU Age Time

Hi Andrew,

Andrew Lunn <andrew@...n.ch> writes:

>> The never ever seeing R/W failure on MDIO bus is not exactly accurate.
>> We had with art (atheros calibration tool) the problem that interrupts
>> were being disabled which lead to MDIO operations running into
>> timout/failing.
>
> Yes, i've seen similar with power management bugs for the MDIO
> driver. But you get a cascade of failures, lots of warnings and error
> prints, it is clear something bad has happened, and the switch is in
> an inconsistent state. So having one more debug print which is also
> inconsistent does no really harm.
>
> Anyway, this whole conversation has taken more effort than just making
> this simple change to remove a few lines of code. So lets drop it and
> move on.

I don't understand nor agree with the fact that sometimes it's OK to not
check for errors, based on one developer assumptions. Not checking
return code is wrong and very likely error-prone.

If you really want to stand for that point, please send a patch series
which turns mv88e6xxx_read() and mv88e6xxx_write() into void functions.
I'd be glad to review and discuss this further. That would indeed make
*all* the driver code simpler.

Thanks,

        Vivien