netdev - Re: [PATCH net] net: phy: fix resume handling

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: <20171213171909.GJ28466@lunn.ch>
Date:   Wed, 13 Dec 2017 18:19:09 +0100
From:   Andrew Lunn <andrew@...n.ch>
To:     Russell King <rmk+kernel@...linux.org.uk>
Cc:     Florian Fainelli <f.fainelli@...il.com>, netdev@...r.kernel.org
Subject: Re: [PATCH net] net: phy: fix resume handling

On Tue, Dec 12, 2017 at 10:45:36AM +0000, Russell King wrote:
> When a PHY has the BMCR_PDOWN bit set, it may decide to ignore writes
> to other registers, or reset the registers to power-on defaults.
> Micrel PHYs do this for their interrupt registers.
> 
> The current structure of phylib tries to enable interrupts before
> resuming (and releasing) the BMCR_PDOWN bit.  This fails, causing
> Micrel PHYs to stop working after a suspend/resume sequence if they
> are using interrupts.
> 
> Fix this by ensuring that the PHY driver resume methods do not take
> the phydev->lock mutex themselves, but the callers of phy_resume()
> take that lock.  This then allows us to move the call to phy_resume()
> before we enable interrupts in phy_start().
> 
> Signed-off-by: Russell King <rmk+kernel@...linux.org.uk>

Reviewed-by: Andrew Lunn <andrew@...n.ch>

    Andrew