From: Arthur Jones <arthur.jones@riverbed.com>
To: "Allan, Bruce W" <bruce.w.allan@intel.com>
Cc: Ben Hutchings <bhutchings@solarflare.com>,
"Kirsher, Jeffrey T" <jeffrey.t.kirsher@intel.com>,
"netdev@vger.kernel.org" <netdev@vger.kernel.org>
Subject: Re: [PATCH] e1000e: workaround missing power down mii control bit on 82571
Date: Thu, 16 Dec 2010 14:14:21 -0800 [thread overview]
Message-ID: <20101216221421.GR18990@ajones-laptop.nbttech.com> (raw)
In-Reply-To: <20101216200425.GO18990@ajones-laptop.nbttech.com>
Hi Bruce, ...
On Thu, Dec 16, 2010 at 12:04:26PM -0800, Arthur Jones wrote:
> Hi Bruce, ...
>
> On Thu, Dec 16, 2010 at 11:28:18AM -0800, Allan, Bruce W wrote:
> > >-----Original Message-----
> > >From: netdev-owner@vger.kernel.org [mailto:netdev-owner@vger.kernel.org] On
> > >Behalf Of Allan, Bruce W
> > >Sent: Thursday, December 16, 2010 11:04 AM
> > >To: Ben Hutchings; Arthur Jones
> > >Cc: Kirsher, Jeffrey T; netdev@vger.kernel.org
> > >Subject: RE: [PATCH] e1000e: workaround missing power down mii control bit on
> > >82571
> > >
> > >>-----Original Message-----
> > >>From: netdev-owner@vger.kernel.org [mailto:netdev-owner@vger.kernel.org] On
> > >>Behalf Of Ben Hutchings
> > >>Sent: Thursday, December 16, 2010 10:57 AM
> > >>To: Arthur Jones
> > >>Cc: Kirsher, Jeffrey T; netdev@vger.kernel.org
> > >>Subject: Re: [PATCH] e1000e: workaround missing power down mii control bit on
> > >>82571
> > >>
> > >>Adding this special case into MDIO access seems like a really nasty
> > >>hack. Surely the callers that set the control register should take care
> > >>of this.
> > >>
> > >>Ben.
> > >
> > >Agreed. I am setting up to repro now to see if it is an actual hardware
> > >issue or just a software bug; either way, this patch is not the correct
> > >approach and I'll follow up shortly.
> > >
> > >Bruce.
> >
> > It's the reset in e1000_set_settings() which ignores that we had previously
> > powered off the Phy. I'll go through the rest of the code and fix up this
> > and any other occurrences of similar issues properly.
>
> Thanks for having a look!
>
> We do a read-modify-write there of
> the PHY control register. We take
> the rest of the bits as being good,
> but, for some reason we don't get the
> power down bit (always reads back
> zero). Is this a known 82571 issue?
> On 82574, e.g., we seem to get the
> power down bit back when we read...
BTW: The 802.3 spec seems to indicate
that this bit _should_ be readable even
when the PHY is powered down (i.e. this
is a PHY bug)...
Arthur
>
> Are you sure you want to spread that
> 82571 specific logic all over the driver?
>
> Arthur
>
> >
> > Thanks for reporting this issue Arthur.
> >
> > Bruce.
next prev parent reply other threads:[~2010-12-16 22:14 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-12-16 18:28 [PATCH] e1000e: workaround missing power down mii control bit on 82571 Arthur Jones
2010-12-16 18:56 ` Ben Hutchings
2010-12-16 19:04 ` Allan, Bruce W
2010-12-16 19:28 ` Allan, Bruce W
2010-12-16 20:04 ` Arthur Jones
2010-12-16 22:14 ` Arthur Jones [this message]
2010-12-17 1:46 ` Allan, Bruce W
2010-12-17 14:04 ` Arthur Jones
2010-12-17 15:53 ` Allan, Bruce W
2010-12-20 15:33 ` Arthur Jones
2010-12-22 20:25 ` Allan, Bruce W
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