Some USB memory sticks not (fully) recognized

[Christian Eggers]

On Thursday, 6 August 2020, 16:29:13 CEST, Christian Eggers wrote:
> Barebox version: 2020.07.0
> Hardware: i.MX6 ULL with external Microchip USB Hub attached
> 
> I got a bug report that some newer USB memory sticks do not work with
> barebox. While with barebox-2020.01 these devices are not recognized at all,
> in barebox-2020.07 I get at least some warnings:
I checked again with an older release of barebox (2019-06). With this version,
the USB drive is detected:

> # usb -s
> usb: USB: scanning bus for devices...
> usb: Bus 001 Device 001: ID 0000:0000 EHCI Host Controller
> usb: Bus 001 Device 002: ID 0424:4916 USB4916
> usb: Bus 001 Device 003: ID 090c:3267 Flash Disk
> Using index 0 for the new disk
> usb: Bus 001 Device 004: ID 0424:494a USB2 Controller Hub
> usb: 4 USB Device(s) found
> Bus 001 Device 001: ID 0000:0000 EHCI Host Controller
> Bus 001 Device 002: ID 0424:4916 USB4916
> Bus 001 Device 003: ID 090c:3267 Flash Disk
> Bus 001 Device 004: ID 0424:494a USB2 Controller Hub

Also mounting the drive works fine. So I guess that this problem may have been 
introduced here:

b1d9837182 ("usb: Change power-on / scanning timeout handling")

Best regards
Christian

> 
> # usb
> 
> > usb: USB: scanning bus for devices...
> > usb1: Bus 001 Device 001: ID 0000:0000 EHCI Host Controller
> > usb1-0: Bus 001 Device 002: ID 0424:4916 USB4916
> > ERROR: usb1-0-4: unable to get descriptor, error 80000000
> > usb1-0-4: Bus 001 Device 003: ID 0424:2240
> > usb1-0-6: Bus 001 Device 004: ID 0424:494a USB2 Controller Hub
> > ERROR: usb1-0-0: unable to get descriptor, error 80000000
> > usb1-0-0: Bus 001 Device 005: ID 090c:3267
> > usb: 5 USB Device(s) found
> 
> Beside the USB memory stick, also one of the hub's internal
> devices is not recognized correctly. The full log output with
> global.loglevel=7 is attached. The first error seems to appear
> 
> in line 233. The USB device descriptor cannot be read:
> > usb1-0-4: usb_control_msg: request: 0x6, requesttype: 0x80, value 0x100
> > index 0x0 length 0x12 imx-usb 2184200.usb at 2184200.of: pipe=8c000483,
> > buffer=8ffca7c0, length=18, req=8ff57580 imx-usb 2184200.usb at 2184200.of:
> > (req=6 (0x6), type=128 (0x80), value=256 (0x100), index=0 imx-usb
> > 2184200.usb at 2184200.of: dev=4, usbsts=0x40081, p[1]=0x18001205, p[2]=0x0
> Under Linux (on the same device), the USB drives work without any noticeable
> problems:
> Linux messages (v5.4):
> > [  111.458582] 000: usb 1-1.1: new high-speed USB device number 5 using
> > ci_hdrc [  111.613740] 000: usb 1-1.1: New USB device found,
> > idVendor=090c, idProduct=3267, bcdDevice=11.00 [  111.613763] 000: usb
> > 1-1.1: New USB device strings: Mfr=1, Product=2, SerialNumber=0 [ 
> > 111.613777] 000: usb 1-1.1: Product: Flash Disk
> > [  111.613784] 000: usb 1-1.1: Manufacturer: USB
> > [  111.615642] 000: usb-storage 1-1.1:1.0: USB Mass Storage device
> > detected
> 
> An usbmon capture for Linux is also attached (USB memory stick is plugged in
> at about packet 99).
> 
> Any hints how I can debug this problem. I've almost now knowledge about
> USB...
> 
> regards
> Christian