netdev - Re: [PATCH net-next v2] net: sfp: soft status and control support

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Message-ID: <20191121185457.GA25745@shell.armlinux.org.uk>
Date:   Thu, 21 Nov 2019 18:54:57 +0000
From:   Russell King - ARM Linux admin <linux@...linux.org.uk>
To:     Ioana Ciornei <ioana.ciornei@....com>
Cc:     Andrew Lunn <andrew@...n.ch>,
        Florian Fainelli <f.fainelli@...il.com>,
        Heiner Kallweit <hkallweit1@...il.com>,
        "David S. Miller" <davem@...emloft.net>,
        "netdev@...r.kernel.org" <netdev@...r.kernel.org>
Subject: Re: [PATCH net-next v2] net: sfp: soft status and control support

On Thu, Nov 21, 2019 at 06:33:41PM +0000, Ioana Ciornei wrote:
> 
> > Subject: Re: [PATCH net-next v2] net: sfp: soft status and control support
> > 
> > On Thu, Nov 21, 2019 at 03:51:07PM +0000, Ioana Ciornei wrote:
> > > > Subject: [PATCH net-next v2] net: sfp: soft status and control
> > > > support
> > > >
> > > > Add support for the soft status and control register, which allows
> > > > TX_FAULT and RX_LOS to be monitored and TX_DISABLE to be set.  We
> > > > make use of this when the board does not support GPIOs for these
> > signals.
> > >
> > > Hi Russell,
> > >
> > > With this addition, shouldn't the following print be removed?
> > >
> > > [    2.967583] sfp sfp-mac4: No tx_disable pin: SFP modules will always be
> > emitting.
> > 
> > No, because modules do not have to provide the soft controls.
> > 
> 
> I understand that the soft controls are optional but can't we read
> byte 93 (Enhanced Options) and see if bit 6 (Optional soft TX_DISABLE control)
> is set or not (ie the soft TX_DISABLE is implemented)?

At cage initialisation time, when we don't know whether there's a
module present or not?

-- 
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