Subject: Re: Driver SFC: Possible bug in LM87 temperature XFP detection code

From: Ben Hutchings <[email-masked]>
Date: Wed, 29 Apr 2009 13:47:40 +0100

On Wed, 2009-04-29 at 10:52 +0200, Jesper Dangaard Brouer wrote:
[...]
> > The "internal" temperature sensor (temp1_input) is in the LM87, which is
> > placed at the corner of the board away from the bracket and the edge
> > connector.
> >
> > The "external" temperature sensor (temp2_input) is in the SFC4000.
> 
> I though this was read from the XFP.

No.

> I was hoping the NIC supported 
> reading i2c stuff from the XFP.  Does it support that? (Robert Olsson 
> wanted to play with this stuff)

That's connected to the PHY and not the controller.  According to the
datasheet for the QT2022, you can read out the EEPROM from MDIO
registers 1.32775-1.33030 (ignoring bits 8-15).  Use the MII ioctl
interface and set phy_id to 0x441 (the formula is 0x400 | (prtad << 5) |
devad).

Ben.

-- 
Ben Hutchings, Senior Software Engineer, Solarflare Communications
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.