netdev - Re: [PATCH] net: dp83tc811: fix link detection and possbile IRQ storm

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: <c6b1897d-e718-975e-1358-857ae4b8d01c@pengutronix.de>
Date:   Fri, 22 Jan 2021 16:07:26 +0100
From:   Marc Kleine-Budde <mkl@...gutronix.de>
To:     netdev@...r.kernel.org
Cc:     Andrew Lunn <andrew@...n.ch>,
        Heiner Kallweit <hkallweit1@...il.com>, kernel@...gutronix.de,
        Dan Murphy <dmurphy@...com>
Subject: Re: [PATCH] net: dp83tc811: fix link detection and possbile IRQ storm

On 1/22/21 4:03 PM, Marc Kleine-Budde wrote:
> In our setup the dp83tc811 is configure to master mode. When there is no slave
> connected the dp83tc811 triggers an interrupt is triggerd, several bits in the
> status registers are set, and te INT_N pin goes low. One of interrupt bits is
> the NO_FRAME interrupt.
> 
> Reading the status register acknowledges the interrupt, but as there is still
> no slave connected, the NO_FRAME interrupt stays set and the INT_N pin low. For
> level triggered IRQs this results in an interrupt storm, as long as the slave
> is not connected. For edge triggered interupts the link change event, when the
> slave comes online, is lost.
> 
> To fix this problem the NO_FRAME interrupt is not enabled. At least in our
> testcase with edge triggered interrupts link change events are now properly
> detected.
> 
> Cc: Dan Murphy <dmurphy@...com>
> Signed-off-by: Marc Kleine-Budde <mkl@...gutronix.de>

Sorry - this patch will not apply as is, I'll send an updated version.

Marc

-- 
Pengutronix e.K.                 | Marc Kleine-Budde           |
Embedded Linux                   | https://www.pengutronix.de  |
Vertretung West/Dortmund         | Phone: +49-231-2826-924     |
Amtsgericht Hildesheim, HRA 2686 | Fax:   +49-5121-206917-5555 |



Download attachment "signature.asc" of type "application/pgp-signature" (489 bytes)