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From: Russell King - ARM Linux <linux@armlinux.org.uk>
To: Andrew Lunn <andrew@lunn.ch>
Cc: Florian Fainelli <f.fainelli@gmail.com>,
	mw@semihalf.com, ymarkman@marvell.com, jason@lakedaemon.net,
	Antoine Tenart <antoine.tenart@bootlin.com>,
	netdev@vger.kernel.org, gregory.clement@bootlin.com,
	kishon@ti.com, nadavh@marvell.com,
	linux-arm-kernel@lists.infradead.org,
	thomas.petazzoni@bootlin.com, miquel.raynal@bootlin.com,
	stefanc@marvell.com, maxime.chevallier@bootlin.com,
	davem@davemloft.net, linux-kernel@vger.kernel.org,
	sebastian.hesselbarth@gmail.com
Subject: Re: [PATCH net-next v2 03/13] net: phy: sfp: warn the user when no tx_disable pin is available
Date: Tue, 8 May 2018 13:45:53 +0100	[thread overview]
Message-ID: <20180508124553.GO16141@n2100.armlinux.org.uk> (raw)
In-Reply-To: <20180505205242.GA2876@lunn.ch>

On Sat, May 05, 2018 at 10:52:42PM +0200, Andrew Lunn wrote:
> On Sat, May 05, 2018 at 01:38:31PM -0700, Florian Fainelli wrote:
> > On May 4, 2018 10:14:25 AM PDT, Andrew Lunn <andrew@lunn.ch> wrote:
> > >On Fri, May 04, 2018 at 10:07:53AM -0700, Florian Fainelli wrote:
> > >> On 05/04/2018 06:56 AM, Antoine Tenart wrote:
> > >> > In case no Tx disable pin is available the SFP modules will always
> > >be
> > >> > emitting. This could be an issue when using modules using laser as
> > >their
> > >> > light source as we would have no way to disable it when the fiber
> > >is
> > >> > removed. This patch adds a warning when registering an SFP cage
> > >which do
> > >> > not have its tx_disable pin wired or available.
> > >> 
> > >> Is this something that was done in a possibly earlier revision of a
> > >> given board design and which was finally fixed? Nothing wrong with
> > >the
> > >> patch, but this seems like a pretty serious board design mistake,
> > >that
> > >> needs to be addressed.
> > >
> > >Hi Florian
> > >
> > >Zii Devel B is like this. Only the "Signal Detect" pin is wired to a
> > >GPIO.
> > 
> 
> > Good point, indeed. BTW what do you think about exposing the SFF's
> > EEPROM and diagnostics through the standard ethtool operations even
> > if we have to keep the description of the SFF as a fixed link in
> > Device Tree because of the unfortunate wiring?
> 
> I believe in Antoine case, all the control plane is broken. He cannot
> read the EEPROM, nor any of the modules pins via GPIOs.

Correct.

> For Zii Devel B, the EEPROM is accessible, and so is the SD pin. What
> is missing is transmit disable. So i would expose it as an SFF module.

Agreed.

-- 
RMK's Patch system: http://www.armlinux.org.uk/developer/patches/
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  reply	other threads:[~2018-05-08 12:46 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-05-04 13:56 [PATCH net-next v2 00/13] net: mvpp2: phylink conversion Antoine Tenart
2018-05-04 13:56 ` [PATCH net-next v2 01/13] net: phy: sfp: make the i2c-bus property really optional Antoine Tenart
2018-05-04 17:03   ` Florian Fainelli
2018-05-04 17:19     ` Antoine Tenart
2018-05-04 13:56 ` [PATCH net-next v2 02/13] net: phy: sfp: handle non-wired SFP connectors Antoine Tenart
2018-05-04 17:04   ` Florian Fainelli
2018-05-04 17:17     ` Andrew Lunn
2018-05-04 17:23     ` Antoine Tenart
2018-05-05 15:39       ` Thomas Petazzoni
2018-05-05 17:48         ` Andrew Lunn
2018-05-08 11:52   ` Russell King - ARM Linux
2018-05-14  9:26     ` Antoine Tenart
2018-05-04 13:56 ` [PATCH net-next v2 03/13] net: phy: sfp: warn the user when no tx_disable pin is available Antoine Tenart
2018-05-04 17:07   ` Florian Fainelli
2018-05-04 17:14     ` Andrew Lunn
2018-05-05 20:38       ` Florian Fainelli
2018-05-05 20:52         ` Andrew Lunn
2018-05-08 12:45           ` Russell King - ARM Linux [this message]
2018-05-08 11:53   ` Russell King - ARM Linux
2018-05-04 13:56 ` [PATCH net-next v2 04/13] net: mvpp2: align the ethtool ops definition Antoine Tenart
2018-05-04 13:56 ` [PATCH net-next v2 05/13] net: mvpp2: phylink support Antoine Tenart
2018-05-04 13:56 ` [PATCH net-next v2 06/13] phy: add 2.5G SGMII mode to the phy_mode enum Antoine Tenart
2018-05-08 12:34   ` Russell King - ARM Linux
2018-05-14  8:37     ` Antoine Tenart
2018-05-04 13:56 ` [PATCH net-next v2 07/13] phy: cp110-comphy: 2.5G SGMII mode Antoine Tenart
2018-05-04 13:56 ` [PATCH net-next v2 08/13] net: mvpp2: 1000baseX support Antoine Tenart
2018-05-04 13:56 ` [PATCH net-next v2 09/13] net: mvpp2: 2500baseX support Antoine Tenart
2018-05-04 13:56 ` [PATCH net-next v2 10/13] arm64: dts: marvell: mcbin: add 10G SFP support Antoine Tenart
2018-05-04 13:56 ` [PATCH net-next v2 11/13] arm64: dts: marvell: mcbin: enable the fourth network interface Antoine Tenart
2018-05-04 13:56 ` [PATCH net-next v2 12/13] arm64: dts: marvell: 7040-db: describe the 10G SFP cage Antoine Tenart
2018-05-04 13:56 ` [PATCH net-next v2 13/13] arm64: dts: marvell: 8040-db: describe the 10G SFP cages Antoine Tenart
2018-05-08  3:18 ` [PATCH net-next v2 00/13] net: mvpp2: phylink conversion David Miller

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