[Xoom Q&A, Help & Troubleshooting] the_bartman:
Some USB OTG problems...

Since moving from CM10.1 to CM11 some USB OTG functionality seems to be missing.

With Xoom (MZ601) stock ROM 4.0.4 and CM10.1 (experimental) i could use a RTL2832 USB stick together with some software defined radio apps (like SDRTouch and Wavesink Plus). Works fine so far. Since CM11, the DVB-stick seems to be recognized by the kernel:

<6>[ 5400.965924] whisper_notify: accy=USB host

<6>[ 5400.966622] cpcap-otg cpcap-otg: SUSPEND --> HOST

<6>[ 5400.972103] tegra-ehci tegra-ehci.0: Tegra EHCI Host Controller

<6>[ 5400.972867] tegra-ehci tegra-ehci.0: new USB bus registered, assigned bus number 2

<6>[ 5401.042359] tegra-ehci tegra-ehci.0: irq 52, io mem 0xc5000000

<6>[ 5401.065351] tegra-ehci tegra-ehci.0: USB 2.0 started, EHCI 1.00

<6>[ 5401.066043] usb usb2: New USB device found, idVendor=1d6b, idProduct=0002

<6>[ 5401.066396] usb usb2: New USB device strings: Mfr=3, Product=2, SerialNumber=1

<6>[ 5401.066968] usb usb2: Product: Tegra EHCI Host Controller

<6>[ 5401.067508] usb usb2: Manufacturer: Linux 2.6.39.4-ElementalX-Xoom-2.0+ ehci_hcd

<6>[ 5401.067811] usb usb2: SerialNumber: tegra-ehci.0

<6>[ 5401.072954] hub 2-0:1.0: USB hub found

<6>[ 5401.073296] hub 2-0:1.0: 1 port detected

<6>[ 5401.478864] mdm6600_wake_work: Call usb_autopm

<6>[ 5401.592347] usb 2-1: new high speed USB device number 2 using tegra-ehci

<6>[ 5401.674048] usb 2-1: New USB device found, idVendor=0bda, idProduct=2832

<6>[ 5401.674335] usb 2-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3

<6>[ 5401.674609] usb 2-1: Product: RTL2832U

<6>[ 5401.674754] usb 2-1: Manufacturer: Generic

<6>[ 5401.674901] usb 2-1: SerialNumber: 77771111153705700

When i try to start the SDR app, i get the error message, that no device could be detected. The driver (https://play.google.com/store/apps/details?id=marto.rtl_tcp_andro&hl=de) says it loads and starts, but it does't work.

I got another USB OTG problem with USB Midi. I use a Teensy 3.1 as a generic USB Midi device (works great under Win7). The device is recognized too:

<6>[ 5781.251045] whisper_notify: accy=none

<6>[ 5781.251414] cpcap-otg cpcap-otg: HOST --> SUSPEND

<6>[ 5781.251559] tegra-ehci tegra-ehci.0: remove, state 4

<6>[ 5781.251760] usb usb2: USB disconnect, device number 1

<6>[ 5781.305093] tegra-ehci tegra-ehci.0: USB bus 2 deregistered

<6>[ 5789.309328] mdm6600_wake_work: Call usb_autopm

<6>[ 5790.745497] whisper_notify: accy=USB host

<6>[ 5790.746174] cpcap-otg cpcap-otg: SUSPEND --> HOST

<6>[ 5790.750588] tegra-ehci tegra-ehci.0: Tegra EHCI Host Controller

<6>[ 5790.751214] tegra-ehci tegra-ehci.0: new USB bus registered, assigned bus number 2

<6>[ 5790.825044] tegra-ehci tegra-ehci.0: irq 52, io mem 0xc5000000

<6>[ 5790.845008] tegra-ehci tegra-ehci.0: USB 2.0 started, EHCI 1.00

<6>[ 5790.845316] usb usb2: New USB device found, idVendor=1d6b, idProduct=0002

<6>[ 5790.845665] usb usb2: New USB device strings: Mfr=3, Product=2, SerialNumber=1

<6>[ 5790.845859] usb usb2: Product: Tegra EHCI Host Controller

<6>[ 5790.846203] usb usb2: Manufacturer: Linux 2.6.39.4-ElementalX-Xoom-2.0+ ehci_hcd

<6>[ 5790.846395] usb usb2: SerialNumber: tegra-ehci.0

<6>[ 5790.848581] hub 2-0:1.0: USB hub found

<6>[ 5790.848811] hub 2-0:1.0: 1 port detected

<6>[ 5791.335168] usb 2-1: new full speed USB device number 2 using tegra-ehci

<6>[ 5791.602907] usb 2-1: New USB device found, idVendor=16c0, idProduct=0485

<6>[ 5791.603469] usb 2-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3

<6>[ 5791.603761] usb 2-1: Product: Teensy MIDI

<6>[ 5791.604258] usb 2-1: Manufacturer: Teensyduino

<6>[ 5791.604536] usb 2-1: SerialNumber: 803180

<6>[ 5791.739959] generic-usb 0003:16C0:0485.0003: hidraw0: USB HID v1.11 Device [Teensyduino Teensy MIDI] on usb-tegra-ehci.0-1/input1

All the apps capable of using USB Midi are saying "no device connected".

The third problem:

If i connect the Teensy Midi device, i get no audio anymore. Seems, that the Xoom thinks it is put into a audio dock and tries to di the audio output via the externa audio connection.

There seems no property in the settings, where i can say to play audio via internal speakers if plugged into a dock (which i will use to connect USB devices over USB OTG).

Any ideas?

Thank you in advance.

Cheers, Bart