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Date: Mon, 22 Sep 2014 17:07:55 +0530
From: Kishon Vijay Abraham I <kishon@ti.com>
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To: Heikki Krogerus <heikki.krogerus@linux.intel.com>
CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Felipe Balbi <balbi@ti.com>, Vivek Gautam <gautam.vivek@samsung.com>,
        <linux-kernel@vger.kernel.org>, <linux-usb@vger.kernel.org>
Subject: Re: [PATCH 2/6] phy: improved lookup method
References: <1408620803-10464-1-git-send-email-heikki.krogerus@linux.intel.com> <1408620803-10464-3-git-send-email-heikki.krogerus@linux.intel.com> <5411C0B2.3060505@ti.com> <20140912140720.GC30816@xps8300> <54130729.5010206@ti.com> <20140915123508.GA16653@xps8300> <20140918102505.GB8567@xps8300>
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Hi,

On Thursday 18 September 2014 03:55 PM, Heikki Krogerus wrote:
> On Mon, Sep 15, 2014 at 03:35:08PM +0300, Heikki Krogerus wrote:
>> On Fri, Sep 12, 2014 at 08:16:01PM +0530, Kishon Vijay Abraham I wrote:
>>> Assume you have 2 phys in your system..
>>> static struct phy_lookup usb_lookup = {
>>> 	.phy_name	= "phy-usb.0",
>>> 	.dev_id		= "usb.0",
>>> 	.con_id		= "usb",
>>> };
>>>
>>> static struct phy_lookup sata_lookup = {
>>> 	.phy_name	= "sata-usb.1",
>>> 	.dev_id		= "sata.0",
>>> 	.con_id		= "sata",
>>> };
>>>
>>> First you do modprobe phy-usb, the probe of USB PHY driver gets invoked and it
>>> creates the PHY. The phy-core will find a free id (now it will be 0) and then
>>> name the phy as phy-usb.0.
>>> Then with modprobe phy-sata, the phy-core will create phy-sata.1.
>>>
>>> This is an ideal case where the .phy_name in phy_lookup matches.
>>>
>>> Consider if the order is flipped and the user does modprobe phy-sata first. The
>>> phy_names won't match anymore (the sata phy device name would be "sata-usb.0").
> 
> Actually, I don't think there would be this problem if we used the
> name of the actual device which is the parent of phy devices, right?

hmm.. but if the parent is a multi-phy phy provider (like pipe3 PHY driver), we
might end up with the same problem.

Thanks
Kishon