netdev - Re: [PATCH v2] r8169: Don't claim WoL works if LanWake flag is not set

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Message-ID: <20151210220255.GB3507@calimero.vinschen.de>
Date:	Thu, 10 Dec 2015 23:02:55 +0100
From:	Corinna Vinschen <vinschen@...hat.com>
To:	Francois Romieu <romieu@...zoreil.com>
Cc:	netdev@...r.kernel.org,
	Realtek linux nic maintainers <nic_swsd@...ltek.com>,
	Chun-Hao Lin <hau@...ltek.com>,
	Hayes Wang <hayeswang@...ltek.com>,
	Corinna Vinschen <vinschen@...hat.com>
Subject: Re: [PATCH v2] r8169: Don't claim WoL works if LanWake flag is not
 set

On Dec 10 21:40, Francois Romieu wrote:
> Corinna Vinschen <vinschen@...hat.com> :
> [...]
> > I could do this (after I could lay my hands on such a board, that is),
> > but I'm not convinced that this makes a lot of sense for two reasons.
> 
> Ok, let's get this change applied. Whatever happens should not be
> hard to manage (I'm thinking about other boards or BIOSes relying on the
> current - broken as it can be - behavior to work correctly).
> 
> [...]
> > 1.  There is no global change in behaviour.  The usual way to handle the
> >     WoL flags is to set the affected method flags and additionally set
> >     LanWake if any of the method flags is set.  The fact that the method
> >     flags don't enable WoL without also settting the LanWake flag is
> >     documented.
> 
> I see no such thing in "7.5 Power Management Function" of the 8168c
> registers datasheet. While Config3 states Magic Packet and Link Up
> dependencies on Config1.PMEn, it says nothing about Config5.LanWake.
> 
> On old 8169 chipsets LanWake is autoloaded from EEPROM.
> 
> Plausible for Config5.{B, M, U}WF ? Ok.
> 
> Documented ? I am genuinely curious to know where.

Ok, I reread the documentation I have, and I got that wrong it seems.
Apparently the LanWake flag enables or disables the LANWAKE/LANWAKEB pin
only but not the other possible PM events.

So, self-NACKed.

It's still a bit weird.  On the machines I tested this on, if I disable
LanWake and shutdown the machine, I can send, e.g., MagicPackets as much
as I like, the machined don't come up.  Isn't it a bit misleading then
if ethtool reports that some WoL method is enabled but it doesn't work?


Corinna

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