From: Andrew Lunn <andrew@lunn•ch>
To: Timur Tabi <timur@codeaurora•org>
Cc: Florian Fainelli <f.fainelli@gmail•com>, netdev@vger•kernel.org
Subject: Re: Need help with mdiobus_register and phy
Date: Sat, 15 Oct 2016 20:02:19 +0200 [thread overview]
Message-ID: <20161015180219.GB6918@lunn.ch> (raw)
In-Reply-To: <58023F90.5070302@codeaurora.org>
On Sat, Oct 15, 2016 at 09:39:12AM -0500, Timur Tabi wrote:
> Florian Fainelli wrote:
> >After reading the spec again, it does not appear to me that a PHY
> >with PDOWN set is guaranteed or even required to respond to other
> >register reads such as MII_PHYID1/2, in which case we may have to
> >implement a MDIO bus reset routine which clears PDOWN for all PHYs
> >that we detect(ed), or as Andrew suggested, utilize the matching by
> >compatible string with the PHY OUI in it.
>
> The 8031 does respond normally when PDOWN is set. However, the ID
> registers are not available when the SerDes bus is also powered
> down. I'll call this PDOWN+. This is a special power-down sequence
> that the at803x driver does on suspend. See my other email for
> details.
So we appear to have two ways to go:
1) Take the SerDes power down out of the suspend code for the at803x.
2) Assume MII_PHYID1/2 registers are not guaranteed to be available
when the PHY is powered down. So get_phy_id should first read
MII_BMCR. If it gets 0xffff, assume there is no PHY there. If the
PDOWN bit is set, power up the PHY. Then reading the ID registers.
Andrew
next prev parent reply other threads:[~2016-10-15 18:03 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-10-13 23:15 Need help with mdiobus_register and phy Timur Tabi
2016-10-14 4:06 ` Andrew Lunn
2016-10-14 11:38 ` Timur Tabi
2016-10-14 12:06 ` Andrew Lunn
2016-10-14 12:39 ` Timur Tabi
2016-10-14 12:49 ` Andrew Lunn
2016-10-14 12:49 ` Timur Tabi
2016-10-14 12:57 ` Andrew Lunn
2016-10-14 13:03 ` Timur Tabi
2016-10-14 13:18 ` Andrew Lunn
2016-10-14 13:28 ` Timur Tabi
2016-10-14 16:57 ` Timur Tabi
2016-10-14 17:25 ` Andrew Lunn
2016-10-14 18:30 ` Timur Tabi
2016-10-15 10:19 ` Florian Fainelli
2016-10-15 14:39 ` Timur Tabi
2016-10-15 18:02 ` Andrew Lunn [this message]
2016-10-15 18:28 ` Timur Tabi
2016-10-17 9:05 ` Zefir Kurtisi
2016-10-17 20:53 ` Timur Tabi
2016-10-18 10:31 ` Zefir Kurtisi
2016-10-18 12:40 ` Timur Tabi
2016-10-19 8:55 ` Zefir Kurtisi
2016-10-19 12:16 ` Timur Tabi
2016-10-20 12:55 ` Zefir Kurtisi
2016-10-21 7:44 ` Zefir Kurtisi
2016-10-21 11:19 ` Timur Tabi
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