linux-kernel - Re: [PATCH net-next 2/3] net: phy: broadcom: Add support for Wake-on-LAN

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: <7de2bc6c-2c74-b1a1-e0a1-e76183b51c56@gmail.com>
Date:   Mon, 8 May 2023 12:12:01 -0700
From:   Florian Fainelli <f.fainelli@...il.com>
To:     Andrew Lunn <andrew@...n.ch>
Cc:     netdev@...r.kernel.org, Doug Berger <opendmb@...il.com>,
        Broadcom internal kernel review list 
        <bcm-kernel-feedback-list@...adcom.com>,
        "David S. Miller" <davem@...emloft.net>,
        Eric Dumazet <edumazet@...gle.com>,
        Jakub Kicinski <kuba@...nel.org>,
        Paolo Abeni <pabeni@...hat.com>,
        Heiner Kallweit <hkallweit1@...il.com>,
        Russell King <linux@...linux.org.uk>,
        Marek Behún <kabel@...nel.org>,
        Peter Geis <pgwipeout@...il.com>,
        Frank <Frank.Sae@...or-comm.com>,
        open list <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH net-next 2/3] net: phy: broadcom: Add support for
 Wake-on-LAN

On 5/8/23 12:09, Andrew Lunn wrote:
>> Because the Wake-on-LAN configuration can be set long before the system
>> is actually put to sleep, we cannot have an interrupt service routine to
>> clear on read the interrupt status register and ensure that new packet
>> matches will be detected.
> 
> Hi Florian
> 
> I assume the interrupt is active low, not an edge. And it will remain
> active until it is cleared? So on resume, don't you need to clear it?
> Otherwise it is already active when entering the next suspend/resume
> cycle.

The interrupt is indeed a level low driven interrupt. The interrupt is 
acknowledged by reading the WOL_INT_STATUS during bcm54xx_config_init() 
which executes during ->probe() and ->resume() and which is a clear on 
read register, this is also necessary to charge the device with the 
wake-up event.
-- 
Florian