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

[Marek Vasut]

On 4/28/21 3:51 AM, Tim Harvey wrote:
> 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.

So interaction with Gadget, that's what I was afraid of.

> 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.

I added Lukasz too.