From: Antoine Tenart <antoine.tenart@bootlin.com>
To: Andrew Lunn <andrew@lunn.ch>
Cc: Antoine Tenart <antoine.tenart@bootlin.com>,
davem@davemloft.net, linux@armlinux.org.uk,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
thomas.petazzoni@bootlin.com, maxime.chevallier@bootlin.com,
gregory.clement@bootlin.com, miquel.raynal@bootlin.com,
nadavh@marvell.com, stefanc@marvell.com, ymarkman@marvell.com,
mw@semihalf.com
Subject: Re: [PATCH net-next 1/2] net: phy: sfp: make the i2c-bus property really optional
Date: Thu, 17 May 2018 14:56:48 +0200 [thread overview]
Message-ID: <20180517125648.GM32746@kwain> (raw)
In-Reply-To: <20180517124127.GG8547@lunn.ch>
Hi Andrew,
On Thu, May 17, 2018 at 02:41:28PM +0200, Andrew Lunn wrote:
> On Thu, May 17, 2018 at 10:29:06AM +0200, Antoine Tenart wrote:
> > The SFF,SFP documentation is clear about making all the DT properties,
> > with the exception of the compatible, optional. In practice this is not
> > the case and without an i2c-bus property provided the SFP code will
> > throw NULL pointer exceptions.
> >
> > This patch is an attempt to fix this.
>
> How usable is an SFF/SFP module without access to the i2c EEPROM? I
> guess this comes down to link speed. Can it be manually configured?
>
> I'm just wondering if we want to make this mandatory? Fail the probe
> if it is not listed?
Yes, the other option would be to fail when probing a cage missing the
i2c description. I'd say a passive module can work without the i2c
EEPROM accessible as it does not need to be configured. I don't know
what would happen with active ones.
So the question is, do we want to enable partially working SFP cages
(ie. probably working with only a subset of SFP modules)?
Thanks!
Antoine
--
Antoine Ténart, Bootlin (formerly Free Electrons)
Embedded Linux and Kernel engineering
https://bootlin.com
next prev parent reply other threads:[~2018-05-17 12:56 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-17 8:29 [PATCH net-next 0/2] net: sfp: small improvements Antoine Tenart
2018-05-17 8:29 ` [PATCH net-next 1/2] net: phy: sfp: make the i2c-bus property really optional Antoine Tenart
2018-05-17 12:41 ` Andrew Lunn
2018-05-17 12:56 ` Antoine Tenart [this message]
2018-05-17 13:04 ` Andrew Lunn
2018-05-17 13:13 ` Antoine Tenart
2018-05-17 15:08 ` Russell King - ARM Linux
2018-05-17 15:01 ` Russell King - ARM Linux
2018-05-17 8:29 ` [PATCH net-next 2/2] net: phy: sfp: warn the user when no tx_disable pin is available Antoine Tenart
2018-05-21 15:51 ` [PATCH net-next 0/2] net: sfp: small improvements David Miller
2018-05-22 9:24 ` Antoine Tenart
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