netdev - Re: [PATCH] net: phy: fix auto-negotiation stall due to unavailable interrupt

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: <129784d6-9020-6d01-4b3d-4740ac61368b@cogentembedded.com>
Date:   Wed, 19 Apr 2017 21:11:43 +0300
From:   Sergei Shtylyov <sergei.shtylyov@...entembedded.com>
To:     Alexander Kochetkov <al.kochet@...il.com>,
        Florian Fainelli <f.fainelli@...il.com>,
        netdev@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] net: phy: fix auto-negotiation stall due to unavailable
 interrupt

Hello!

On 04/19/2017 04:46 PM, Alexander Kochetkov wrote:

> The problem I fix related to SMSC LAN8710/LAN8720 PHY handled using
> interrupts. During power-up cycle the PHY do auto-negotiation, generate
> interrupt and set BMSR_ANEGCOMPLETE flag. Interrupt is handled by PHY
> state machine but doesn't update link because PHY is in PHY_READY state.
> After some time MAC bring up and connect with PHY. It start PHY using
> phy_start(). During startup PHY change state to PHY_AN but doesn't
> set BMCR_ANRESTART flag due to genphy_config_aneg() doesn't update MII_BMCR
> because there no new to advertising. As a result, state machine wait for
           ^^^^^^^^^^^^    ^^^^^^^^^^^
    There is no new what? Advertize, maybe?

> interrupt from PHY and nether get "link is up". Because BMSR_ANEGCOMPLETE
                          ^^^^^^
    Never, neither? :-)

> already set the patch schedule check link without waiting interrupt.
> In case genphy_config_aneg() update MII_BMCR and set BMCR_ANRESTART
> flag, BMSR_ANEGCOMPLETE will be cleared and state machine will continue
> on auto-negotiation interrupt.
>
> Signed-off-by: Alexander Kochetkov <al.kochet@...il.com>
[...]

MBR, Sergei