[PATCH V2] USB: initialize or shutdown PHY when add or remove host controller

[Chao Xie]

correct for irq. irq number is get by gludriver, while irq is
requested by EHCO HCD.

On Fri, Jun 21, 2013 at 9:07 AM, Chao Xie <xiechao.mail at gmail.com> wrote:
> On Fri, Jun 21, 2013 at 1:25 AM, Alan Stern <stern at rowland.harvard.edu> 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.
>>
>
> From device point of view, EHCI is a standlone component. It has the
> standard sepcification, so each
> SOC vendor has EHCI HCD need to follow the standards. Then we have
> common EHCI HCD driver.
> The PHY is outside of EHCI component, each SOC vendor may have
> different PHY implementation. Then
> we have PHY driver.
> The EHCI glue driver ehci-xxx works like a SOC depended driver. It is
> its duty to handle the'
> relationship between the EHCI HCD driver and PHY driver.
> It is same as clk, irq requested by ehci-xxx driver.
>
> So i think add a flag and use usb_get_phy() is not very good.
> It is bette to make ehci-xxx to do the phy getting and EHCI HCD
> initialize it and shut down as the patch did, or let ehci-xxx to
> handle the PHY as Roger said.
>
> Based on the generic work is not too much, and does not look so
> meaningful. I suggest that let to echi-xxx
> do it.
>
>> Alan Stern
>>