Re: [Bugme-new] [Bug 33042] New: Marvell 88E1145 phy configured incorrectly in fiber mode

From: Andy Fleming <afleming@gmail.com>
To: Alex Dubov <oakad@yahoo.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	David Daney <ddaney@caviumnetworks.com>,
	netdev@vger.kernel.org, bugzilla-daemon@bugzilla.kernel.org,
	bugme-daemon@bugzilla.kernel.org,
	Grant Likely <grant.likely@secretlab.ca>,
	Andy Fleming <afleming@freescale.com>
Subject: Re: [Bugme-new] [Bug 33042] New: Marvell 88E1145 phy configured incorrectly in fiber mode
Date: Fri, 15 Apr 2011 15:57:04 -0500	[thread overview]
Message-ID: <BANLkTikJ60ND7s5-jfGTBDG3BoM-294CSA@mail.gmail.com> (raw)
In-Reply-To: <903944.53826.qm@web37604.mail.mud.yahoo.com>

On Thu, Apr 14, 2011 at 2:59 AM, Alex Dubov <oakad@yahoo.com> wrote:
>
>
> --- On Thu, 14/4/11, Andy Fleming <afleming@gmail.com> wrote:
>
>>
>> I've just rewritten the U-Boot code for PHY management, so
>> I'd be
>> interested in hearing if this breaks your board.  But
>> what's
>> interesting to me is that, in order for U-Boot to report
>> that the link
>> is a "fiber" link, something had to set the TSEC_FIBER
>> flag, and only
>> one PHY in the public source did.  This implies to me
>> that your board
>> isn't supported by mainline U-Boot, and suggests that
>> someone may have
>> modified the 88e1145 driver. Otherwise, I don't see any
>> fiber-related
>> differences between the U-Boot 1145 driver, and the Linux
>> one.
>
> I had not seen any difference, that's true. But the problem somehow
> creeps in.
>
> The u-boot is standard stock u-boot pulled from the recent git,
> no special configuration involved.

Are you seeing this message when you run ethernet in u-boot?

"Speed: 1000, full duplex, fiber mode"

Because that last part only shows up if someone sets TSEC_FIBER in the
tsec's "flags" field...

> I tried to prevent kernel from reconfiguring the phy, but to no avail.
> It seems very weird to me, because I did quite a lot of testing with
> u-boot and network just works on that interface. However, when kernel
> starts booting it suddenly looses the ability to talk to it.

Believe me, I feel your pain.  These devices are often remarkably
fickle. The kernel tries to be
more robust, but sometimes the PHYs just don't like to be touched at all.

You could probably change to use a fixed link by removing the
phy-handle property from your ethernet device node, and adding:
"fixed-link=<0 1000 1 0 0>".  If that works, then the issue is that
Linux is breaking something when it connects. It might be good enough
for you to use fixed-link, though it would be good to actually find
out what's going wrong with the PHY driver.

Andy