From: Andrew Lunn <andrew@lunn•ch>
To: Sergei Shtylyov <sergei.shtylyov@cogentembedded•com>
Cc: "Roger Quadros" <rogerq@ti•com>,
"Uwe Kleine-König" <u.kleine-koenig@pengutronix•de>,
grant.likely@linaro•org, robh+dt@kernel•org,
devicetree@vger•kernel.org, f.fainelli@gmail•com,
netdev@vger•kernel.org, frowand.list@gmail•com,
pawel.moll@arm•com, mark.rutland@arm•com,
ijc+devicetree@hellion•org.uk, galak@codeaurora•org,
linux-kernel@vger•kernel.org,
"Linus Walleij" <linus.walleij@linaro•org>
Subject: Re: [PATCH RFT 1/2] phylib: add device reset GPIO support
Date: Sat, 14 May 2016 21:50:16 +0200 [thread overview]
Message-ID: <20160514195016.GC26220@lunn.ch> (raw)
In-Reply-To: <cc232c9e-ef25-482d-0978-cbdfe03bad22@cogentembedded.com>
On Sat, May 14, 2016 at 10:36:38PM +0300, Sergei Shtylyov wrote:
> Hello.
>
> On 05/14/2016 02:44 AM, Andrew Lunn wrote:
>
> >>>>>Another issue is that on some boards we have one reset line tied to
> >>>>>multiple PHYs.How do we prevent multiple resets being taking place when each of
> >>>>>the PHYs are registered?
> >>>>
> >>>> My patch just doesn't address this case -- it's about the
> >>>>individual resets only.
> >>>
> >>>This actually needs to be addresses a layer above. What you have is a
> >>>bus reset, not a device reset.
> >>
> >> No.
> >> There's simply no such thing as a bus reset for the xMII/MDIO
> >>busses, there's simply no reset signaling on them. Every device has
> >>its own reset signal and its own timing requirements.
> >
> >Except in the case above, where two phys are sharing the same reset
> >signal. So although it is not part of the mdio standard to have a bus
> >reset, this is in effect what the gpio line is doing, resetting all
> >devices on the bus. If you don't model that as a bus reset, how do you
> >model it?
>
> I'm not suggesting that the shared reset should be handled by my
> patch. Contrariwise, I suggested to use the mii_bus::reset() method
I think we miss understood each other somewhere.
Your code is great for one gpio reset line for one phy.
I think there could be similar code one layer above to handle one gpio
line for multiple phys.
Andrew
next prev parent reply other threads:[~2016-05-14 19:50 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-08 22:21 [PATCH RFT 0/2] Teach phylib hard-resetting devices Sergei Shtylyov
2016-04-08 22:22 ` [PATCH RFT 1/2] phylib: add device reset GPIO support Sergei Shtylyov
2016-04-11 19:25 ` Rob Herring
2016-04-11 19:28 ` Sergei Shtylyov
2016-04-11 22:46 ` Rob Herring
2016-04-08 22:25 ` [PATCH RFT 2/2] macb: kill PHY reset code Sergei Shtylyov
2016-04-11 2:28 ` Andrew Lunn
2016-04-11 17:41 ` Sergei Shtylyov
2016-04-11 18:19 ` Andrew Lunn
2016-04-11 18:39 ` Sergei Shtylyov
[not found] ` <570BEF46.7060105-M4DtvfQ/ZS1MRgGoP+s0PdBPR1lH4CV8@public.gmane.org>
2016-04-11 18:51 ` Andrew Lunn
[not found] ` <20160411185115.GA30623-g2DYL2Zd6BY@public.gmane.org>
2016-04-11 19:01 ` Sergei Shtylyov
2016-04-26 10:24 ` [PATCH] ARM: dts: at91: VInCo: fix phy reset gpio flag Nicolas Ferre
2016-04-26 17:17 ` David Miller
2016-04-26 18:27 ` Sergei Shtylyov
2016-04-27 7:15 ` Nicolas Ferre
2016-04-26 18:25 ` Sergei Shtylyov
2016-04-12 9:23 ` [PATCH RFT 2/2] macb: kill PHY reset code Nicolas Ferre
2016-04-12 9:22 ` Nicolas Ferre
2016-04-12 13:40 ` Andrew Lunn
2016-04-12 14:45 ` Nicolas Ferre
2016-04-12 13:54 ` Sergei Shtylyov
2016-04-12 14:57 ` Nicolas Ferre
2016-04-28 22:12 ` [PATCH RFT 1/2] phylib: add device reset GPIO support Sergei Shtylyov
2016-05-03 17:03 ` Rob Herring
2016-05-10 18:32 ` Florian Fainelli
[not found] ` <5732294F.3060606-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2016-05-10 19:11 ` Sergei Shtylyov
[not found] ` <5732327A.6080203-M4DtvfQ/ZS1MRgGoP+s0PdBPR1lH4CV8@public.gmane.org>
2016-05-10 19:13 ` Florian Fainelli
[not found] ` <3641492.klKRrvS8tr-gHKXc3Y1Z8zGSmamagVegGFoWSdPRAKMAL8bYrjMMd8@public.gmane.org>
2016-05-12 18:42 ` Uwe Kleine-König
2016-05-12 21:35 ` Sergei Shtylyov
2016-05-13 4:06 ` Andrew Lunn
2016-05-13 21:16 ` Sergei Shtylyov
2016-05-13 7:06 ` Uwe Kleine-König
2016-05-13 21:49 ` Sergei Shtylyov
2016-05-13 19:18 ` Sergei Shtylyov
2016-05-14 21:14 ` Sergei Shtylyov
2016-05-13 9:07 ` Roger Quadros
2016-05-13 19:36 ` Sergei Shtylyov
2016-05-13 20:44 ` Andrew Lunn
2016-05-13 20:56 ` Sergei Shtylyov
2016-05-13 23:44 ` Andrew Lunn
2016-05-14 19:36 ` Sergei Shtylyov
2016-05-14 19:50 ` Andrew Lunn [this message]
2016-05-14 21:46 ` Sergei Shtylyov
[not found] ` <34922ff9-e566-4829-a631-54ce07cbb325-M4DtvfQ/ZS1MRgGoP+s0PdBPR1lH4CV8@public.gmane.org>
2016-05-15 15:23 ` Andrew Lunn
[not found] ` <20160515152339.GA9021-g2DYL2Zd6BY@public.gmane.org>
2016-05-19 13:40 ` Sergei Shtylyov
2016-05-16 8:51 ` Roger Quadros
2016-05-26 9:00 ` Linus Walleij
2016-05-26 19:00 ` Uwe Kleine-König
2016-05-30 14:57 ` Linus Walleij
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