Re: [PATCH v1] usb: xhci: plat: Add USB 3.0 phy support

[Klaus Kudielka <klaus.kudielka@gmail.com>]

On 10.05.2023 05:16, Stanley Chang[昌育德] wrote:
> Hi Klaus,
>
>>
>> I'm booting 6.4-rc1 on a Turris Omnia
>> (arm/boot/dts/armada-385-turris-omnia.dts)
>> and get those error messages:
>> [    0.231609] xhci-hcd f10f0000.usb3: xhci_plat_probe get usb3phy fail
>> (ret=-6)
>> [    0.239716] xhci-hcd f10f8000.usb3: xhci_plat_probe get usb3phy fail
>> (ret=-6)
>>
>> It looks like a cosmetic issue with error codes, but maybe it can be fixed?
>>
> 1. I checked arm/boot/dts/armada-385-turris-omnia.dts.
> The xhci node doesn't seem to have usb-phy.
> In this case it should get error code -ENODEV (-19).
> I'm not sure why the error code is -ENXIO (-6).
> Can you provide more details?

I have CONFIG_USB_PHY disabled. In that case, devm_usb_get_phy_by_phandle
is declared static inline and returns -ENXIO. See include/linux/usb/phy.h.

> 2. This error message will be printed only when getting the usb3 phy fails.
> And usb_phy set to NULL, It does not affect the original behavior.
> Maybe I'm missing checking -ENXIO or some other error code.
> I can delete this log according to usb2 phy situation.

Checking for -ENXIO in addition to -ENODEV would cover the !CONFIG_USB_PHY
case, I guess. Whether there are other "false alarm" cases, I don't know.

> Thanks,
> Stanley

Best regards, Klaus