From: Felipe Balbi <balbi@ti.com>
To: Alan Stern <stern@rowland.harvard.edu>
Cc: Felipe Balbi <balbi@ti.com>, Chao Xie <xiechao.mail@gmail.com>,
Roger Quadros <rogerq@ti.com>, Chao Xie <chao.xie@marvell.com>,
Greg KH <gregkh@linuxfoundation.org>,
"linux-usb@vger.kernel.org" <linux-usb@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH V2] USB: initialize or shutdown PHY when add or remove host controller
Date: Mon, 24 Jun 2013 22:36:43 +0300 [thread overview]
Message-ID: <20130624193643.GC11815@arwen.pp.htv.fi> (raw)
In-Reply-To: <Pine.LNX.4.44L0.1306201319580.2063-100000@iolanthe.rowland.org>
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On Thu, Jun 20, 2013 at 01:25:31PM -0400, Alan Stern wrote:
> On Thu, 20 Jun 2013, Felipe Balbi wrote:
>
> > > In fact, the PHY setting and handling is related to platform or SOC,
> > > and for different SOC they can
> > > have same EHCI HCD but they PHY handling can be different.
> > > Omap'a case is the example, and i think some other vendors may have
> > > silimar cases.
> > > From above point, It is better to leave the PHY initialization and
> > > shutdown to be done by each echi-xxx driver.
> > >
> > > So Alan and Felipe
> > > What are your ideas about it?
> >
> > If we have so many exceptions, then sure. But eventually, the common
> > case should be added generically with a flag so that non-generic cases
> > (like OMAP) can request to handle the PHY by themselves.
> >
> > Alan ?
>
> I don't have very strong feelings about this; Felipe has much more
> experience with these things.
>
> However, when the common case is added into the core, the simplest way
> to indicate that the HCD wants to handle the PHY(s) by itself will be
> to leave hcd->phy set to NULL or an ERR_PTR value.
>
> One important thing that hasn't been pointed out yet: When we move
> these calls into the core, the same patch must also remove those calls
> from the glue drivers that currently do set hcd->phy. And it must make
> sure that the glue drivers which handle the PHY by themselves do not
> set hcd->phy.
perfect summary. Perhaps Roger could already work on private PHY handle
for ehci-omap.c and later we can start moving generic case to usbcore
without having to touch ehci-omap.c at all. Roger, any commetns ?
--
balbi
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next prev parent reply other threads:[~2013-06-24 19:37 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-06-19 2:31 [PATCH V2] USB: initialize or shutdown PHY when add or remove host controller Chao Xie
2013-06-19 2:48 ` Greg KH
2013-06-19 3:23 ` Chao Xie
2013-06-19 7:51 ` Roger Quadros
2013-06-20 0:53 ` Chao Xie
2013-06-20 12:17 ` Felipe Balbi
2013-06-20 17:25 ` Alan Stern
2013-06-21 1:07 ` Chao Xie
2013-06-21 1:27 ` Chao Xie
2013-06-24 19:45 ` Felipe Balbi
2013-06-25 1:25 ` Chao Xie
2013-06-25 3:33 ` Felipe Balbi
2013-06-24 19:36 ` Felipe Balbi [this message]
2013-06-25 13:37 ` Roger Quadros
2013-06-25 13:43 ` Felipe Balbi
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