Re: [PATCH v2 0/2] usb: host: xhci: rcar: fix the quirks setting of XHCI_NO_64BIT_SUPPORT

[Mathias Nyman <mathias.nyman@linux.intel.com>]

>>> isn't the following enough?
>>>
>>> @@ -4886,7 +4886,7 @@ int xhci_gen_setup(struct usb_hcd *hcd, xhci_get_quirks_t get_quirks)
>>>   		xhci->hcc_params2 = readl(&xhci->cap_regs->hcc_params2);
>>>   	xhci_print_registers(xhci);
>>>
>>> -	xhci->quirks = quirks;
>>> +	xhci->quirks |= quirks;
>>>
>>>   	get_quirks(dev, xhci);
>>
>> Thank you for the comment!
>> You're correct. This also can resolve the issue.
>> Do you prefer such a simple patch?
>> At least, I prefer such a simple patch :)
>
> I'll defer that to Mathias :-)
>

I think that xhci->quirks |= quirks will do as a rc fix.

looks like setting xhci->quirks need some generic cleanup for usb-next.
Now in 4.7-rc1 we set xhci->quirks before xhci_gen_setup in xhci_priv_init_quirk(),
and during xhci_gen_setup() when copying module parameters quirk, and when calling
the get_quirk() callback.

There is nothing special happening between xhci_priv_init_quirk and when calling
get_quirks() in xhci_gen_setup() that need quirks to be set in two stages.

xhci pci drivers only use the get_quirk callback, platform drivers use both.

Looks like the get_quirk() callback is a legacy thing from when the memory for
the xhci struct was allocated in xhci_gen_setup, and xhci->quirks could only be
set after that.

Now xhci struct is part of the usb_hcd, so we could probably get rid of the get_quirk
callback alltogether by setting the pci quirks in xhci_pci_setup

-Mathias