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

From: [email-masked] (Pavel Machek)
Date: Fri, 25 Mar 2016 22:09:44 +0100

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.

gzipped config is attached.

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.

Best regards,

									Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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