usb: gadget breakage on N900: bind UDC by name passed via usb_gadget_driver structure

[Ruslan Bilovol]

On Sat, Mar 26, 2016 at 11:32 PM, Ruslan Bilovol
<ruslan.bilovol at gmail.com> wrote:
> Hi
>
> On Fri, Mar 25, 2016 at 11:09 PM, Pavel Machek <pavel at ucw.cz> wrote:
>> Hi!
>>
>>> OK, so at last I finished charging of my N900; found 1.8V USB
>>> to UART adapter and soldered it to the phone.
>>>
>>> I managed to boot N900 with working USB gadget (builtin g_ether)
>>> in boardfile mode, can ping it from PC and transfer data. I don't
>>> see any issue (except of musb name issue in twl phy driver, I've
>>> already sent a fix for that: https://lkml.org/lkml/2016/3/24/670 )
>>>
>>> Pavel, I still don't see how you've got your issue, please share
>>> more detials
>>
>> Ok, let me try. I undid all the changes in drivers/phy drivers/usb and
>> include/linux/usb . I have all the gadget stuff built-in, so that I
>> could use nfsroot, but this is boot from mmcblk.
>
> So do you mean you use original rootfs that was shipeed with N900?
>
>>
>> gzipped config is attached.
>
> Thanks, I'll try that
>
>>
>> PC is unable to work with the gadget:
>>
>> [256526.716099] usb 2-1: new full-speed USB device number 52 using
>> uhci_hcd
>> [256526.832091] usb 2-1: device descriptor read/64, error -32
>> [256527.052095] usb 2-1: device descriptor read/64, error -32
>> [256527.268160] usb 2-1: new full-speed USB device number 53 using
>> uhci_hcd
>> [256527.388121] usb 2-1: device descriptor read/64, error -32
>> [256527.608116] usb 2-1: device descriptor read/64, error -32
>> [256527.824170] usb 2-1: new full-speed USB device number 54 using
>> uhci_hcd
>> [256527.851175] usb 2-1: device descriptor read/8, error -32
>> [256527.975175] usb 2-1: device descriptor read/8, error -32
>> [256528.188133] usb 2-1: new full-speed USB device number 55 using
>> uhci_hcd
>> [256528.218184] usb 2-1: device descriptor read/8, error -32
>> [256528.343183] usb 2-1: device descriptor read/8, error -32
>> [256528.444314] usb usb2-port1: unable to enumerate USB device
>>
>> Dmesg from the n900 is attached as /tmp/delme.gz. I did _not_ apply
>> the patch from https://lkml.org/lkml/2016/3/24/670 , yet, as I'm using
>> devicetree boot.
>
> Hmm.. don't see anything strange in the boot log related to USB,
> I'll try your config

After looking into your config and boot log again, I see you use kernel
4.4, whereas the patch you've told about ("usb: gadget: bind UDC by name
passed via usb_gadget_driver structure") was merged only into 4.5 kernel.
Could you please try vanilla v4.5 with your config and see if it helps?

Best regards,
Ruslan Bilovol