[PATCH 1/3] usb: ehci-mx6: move mode set/detect to probe

[Tim Harvey]

On Tue, Apr 27, 2021 at 10:45 AM Marek Vasut <marex at denx.de> wrote:
>
> On 4/27/21 7:08 PM, Tim Harvey wrote:
> > There is no need to set and/or detect mode in of_to_plat and
> > accessing phy registers at that point before device power domain and
> > clock are enabled will cause hangs on platforms such as IMX8M Mini.
> >
> > Move the mode set/detect from of_to_plat into the probe and remove
> > the unnecessary of_to_plat.
> >
> > Signed-off-by: Tim Harvey <tharvey at gateworks.com>
> > ---
> >   drivers/usb/host/ehci-mx6.c | 42 ++++++++++++++-----------------------
> >   1 file changed, 16 insertions(+), 26 deletions(-)
> >
> > diff --git a/drivers/usb/host/ehci-mx6.c b/drivers/usb/host/ehci-mx6.c
> > index 06be9deaaa..c2dfe49012 100644
> > --- a/drivers/usb/host/ehci-mx6.c
> > +++ b/drivers/usb/host/ehci-mx6.c
> > @@ -539,28 +539,6 @@ static int ehci_usb_phy_mode(struct udevice *dev)
> >       return 0;
> >   }
> >
> > -static int ehci_usb_of_to_plat(struct udevice *dev)
> > -{
> > -     struct usb_plat *plat = dev_get_plat(dev);
> > -     enum usb_dr_mode dr_mode;
> > -
> > -     dr_mode = usb_get_dr_mode(dev_ofnode(dev));
> > -
> > -     switch (dr_mode) {
> > -     case USB_DR_MODE_HOST:
> > -             plat->init_type = USB_INIT_HOST;
> > -             break;
> > -     case USB_DR_MODE_PERIPHERAL:
> > -             plat->init_type = USB_INIT_DEVICE;
> > -             break;
> > -     case USB_DR_MODE_OTG:
> > -     case USB_DR_MODE_UNKNOWN:
> > -             return ehci_usb_phy_mode(dev);
> > -     };
> > -
> > -     return 0;
> > -}
> > -
>
> [...]
>
> > @@ -764,7 +755,6 @@ U_BOOT_DRIVER(usb_mx6) = {
> >       .name   = "ehci_mx6",
> >       .id     = UCLASS_USB,
> >       .of_match = mx6_usb_ids,
> > -     .of_to_plat = ehci_usb_of_to_plat,
>
> I wonder why it was implemented in of_to_plat originally , maybe there
> is some reason for that ?

Marek,

Looking back the commit that added the ehci_usb_ofdata_to_platdata was:
cccbddc38c43 ("usb: ehci-mx6: implement ofdata_to_platdata")

Before that there was a board-specific function that would set the
usb_plat->init_type.

The only reason to set usb_plat->init_type in of_to_plat would be so
that drivers/usb/host/usb-uclass.c would have knowledge of it but I
only see that it is set there in usb_setup_ehci_gadget.

I added Peng, Stefano, and Simon to the thread to see if they see an
issue with doing away with of_to_plat setting the usb_plat->init_type
prior to probe.

Tim