USB on embedded Linux - TI hub TUSB2046B doesn't detect USB devices

Question

I have a problem on embedded platform with very limited toolchain. I have TI Hub connected to USB host on chip. This hub seems to be detected properly, but sierra wireless SL6087 device that I connect to it, doesn't appear in system. Unfortunately I can't use USB Device Filesystem - I have no /proc/bus/usb. What I can do is read /sys direct.

I get following system log with and without modul connected. I also don't see any communication on D+ and D- lines. kernel 2.6.21.

# dmesg | grep -e hub -e usb
usbcore: registered new interface driver usbfs
usbcore: registered new interface driver hub
usbcore: registered new device driver usb

usbmon: debugfs is not available
rt3xxx-ohci rt3xxx-ohci: roothub.a 02000202 POTPGT=2 NPS NDP=2(2)
rt3xxx-ohci rt3xxx-ohci: roothub.b 00000000 PPCM=0000 DR=0000
rt3xxx-ohci rt3xxx-ohci: roothub.status 00008000 DRWE
rt3xxx-ohci rt3xxx-ohci: roothub.portstatus [0] 0x00000100 PPS
rt3xxx-ohci rt3xxx-ohci: roothub.portstatus [1] 0x00000100 PPS
usb usb1: default language 0x0409
usb usb1: new device strings: Mfr=3, Product=2, SerialNumber=1
usb usb1: Product: RT3xxx OHCI Controller
usb usb1: Manufacturer: Linux 2.6.21 ohci_hcd
usb usb1: SerialNumber: rt3xxx-ohci
usb usb1: uevent
usb usb1: usb_probe_device
usb usb1: configuration #1 chosen from 1 choice
usb usb1: adding 1-0:1.0 (config #1, interface 0)
usb 1-0:1.0: uevent
hub 1-0:1.0: usb_probe_interface
hub 1-0:1.0: usb_probe_interface - got id
hub 1-0:1.0: USB hub found
hub 1-0:1.0: 2 ports detected
hub 1-0:1.0: standalone hub
hub 1-0:1.0: no power switching (usb 1.0)
hub 1-0:1.0: global over-current protection
hub 1-0:1.0: power on to power good time: 4ms
hub 1-0:1.0: local power source is good
hub 1-0:1.0: no over-current condition exists
hub 1-0:1.0: trying to enable port power on non-switchable hub
hub 1-0:1.0: state 7 ports 2 chg 0000 evt 0000
usbcore: registered new interface driver usbserial
drivers/usb/serial/usb-serial.c: USB Serial support registered for generic
usbcore: registered new interface driver usbserial_generic
drivers/usb/serial/usb-serial.c: USB Serial Driver core
drivers/usb/serial/usb-serial.c: USB Serial support registered for Sierra USB modem
usbcore: registered new interface driver sierra    
drivers/usb/serial/sierra.c: USB Driver for Sierra Wireless USB modems: v.1.7.40

sleeves sleeves · Accepted Answer · 2011-12-30T13:56:02

Check your VBUS. Are you getting the +5V going to your devices? When you connect the device, is there any log file change? These are the things I would try. Sometimes it is as simple as following an enable/reset line on the schematic and setting a GPIO properly.

NOTE: If you do get a log file change when you insert the device, then you probably are just missing the other side of the process; the driver.

USB on embedded Linux - TI hub TUSB2046B doesn't detect USB devices

1 Answers