From: Andrew Lunn <andrew@lunn.ch>
To: Antoine Tenart <antoine.tenart@bootlin.com>
Cc: 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 15:04:06 +0200 [thread overview]
Message-ID: <20180517130406.GH8547@lunn.ch> (raw)
In-Reply-To: <20180517125648.GM32746@kwain>
On Thu, May 17, 2018 at 02:56:48PM +0200, Antoine Tenart wrote:
> 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.
Hi Antoine
I was thinking about how it reads the bit rate from the EEPROM. From
that it determines what mode the MAC could use, 1000-Base-X,
2500-Base-X, etc. Can you still configure this correctly via ethtool,
if you don't have the bitrate information?
Andrew
next prev parent reply other threads:[~2018-05-17 13:04 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
2018-05-17 13:04 ` Andrew Lunn [this message]
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
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20180517130406.GH8547@lunn.ch \
--to=andrew@lunn.ch \
--cc=antoine.tenart@bootlin.com \
--cc=davem@davemloft.net \
--cc=gregory.clement@bootlin.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux@armlinux.org.uk \
--cc=maxime.chevallier@bootlin.com \
--cc=miquel.raynal@bootlin.com \
--cc=mw@semihalf.com \
--cc=nadavh@marvell.com \
--cc=netdev@vger.kernel.org \
--cc=stefanc@marvell.com \
--cc=thomas.petazzoni@bootlin.com \
--cc=ymarkman@marvell.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).