Re: [PATCH] usb: phy: Move R-Car Gen2 driver registration to postcore_inictall

[Greg KH <greg@kroah.com>]

On Wed, Oct 30, 2013 at 01:56:25PM +0400, Valentine wrote:
> On 10/30/2013 03:57 AM, Greg KH wrote:
> > On Tue, Oct 29, 2013 at 09:19:09PM +0400, Valentine wrote:
> >> On 10/29/2013 09:00 PM, Laurent Pinchart wrote:
> >>> Hi Valentine,
> >>>
> >>> Thank you for the patch.
> >>>
> >>> On Tuesday 29 October 2013 20:21:06 Valentine Barshak wrote:
> >>>> USB phy controls USB channels 0 and 2 which are shared between
> >>>> PCI USB host controllers and USBHS/USBSS respectively.
> >>>>
> >>>> This Initializes USB phy driver earlier because we need it
> >>>> before PCI USB host controllers are initialized.
> >>>
> >>> Can't you use deferred probing ?
> >>
> >> No, unfortunately this doesn't work with PCI.
> >> We need the USB PHY set up before the PCI driver starts.
> >> PCI controllers should be initialized via subsys_initcall and can't be built as a module.
> >> Deferred probing is done at late_initcall and that's far too late in this case.
> >>
> >> The MXS USB phy uses the similar approach, initializing the driver via postcore_initcall.
> >
> > I _HATE_ this "make this driver later than the others" mess.  I'll not
> 
> This is actually "make this driver before the others" mess.
> 
> > take patches that move drivers to different initcalls, sorry.  Please
> > fix up the link order, or use deferred probing, as that is why it was
> > created.
> >
> 
> This is needed for the PCI EHCI/OHCI drivers to operate correctly on R-Car Gen platform
> since it has built-in PCI host controllers that share USB I/O with USBHS/USBSS devices.
> The phy has to be configured before the PCI EHCI/OHCI devices are probed.
> 
> I'd really appreciate if you could give me a hint on how to fix the PCI EHCI/OHCI driver
> to use deferred probing, or fix the link order without creating a bigger mess.

Just change the PCI driver to use deferred probing, it isn't that hard
to do so.

good luck,

greg k-h