On Thu, 18 Nov 2010 david.schueler@xxxxxxxxxxxxxxxxxxx wrote: > >If you plug your FTDI device into bus 1 instead of bus 2, does the > >weather-station program then work okay? > > No. I plugged it to bus 3 and 4 also with no luck. > See the files while program hang: > > Server ~ # lsusb > Bus 002 Device 001: ID 1d6b:0002 > Bus 003 Device 002: ID 0403:6001 Future Technology Devices International, > Ltd FT232 USB-Serial (UART) IC > Bus 003 Device 003: ID 0403:6001 Future Technology Devices International, > Ltd FT232 USB-Serial (UART) IC > Bus 003 Device 001: ID 1d6b:0001 > Bus 001 Device 001: ID 1d6b:0002 > Bus 004 Device 002: ID 0403:6001 Future Technology Devices International, > Ltd FT232 USB-Serial (UART) IC > Bus 004 Device 001: ID 1d6b:0001 Which of these three FTDI devices is the one that's hanging? > Server ~ # > Server ~ # mount -t debugfs none /sys/kernel/debug > Server ~ # > Server ~ # cat /sys/kernel/debug/usb/ohci/0000\:00\:02.0/async > cat: /sys/kernel/debug/usb/ohci/0000:00:02.0/async: Operation not permitted That's very suspicious. In fact, I can't imagine how it happened. Does the file not have read permission? Probably the information we need is buried in that file... > Server ~ # cat /sys/kernel/debug/usb/ohci/0000\:00\:02.0/periodic > size = 32 > Server ~ # cat /sys/kernel/debug/usb/ohci/0000\:00\:02.0/registers > bus pci, device 0000:00:02.0 > OHCI Host Controller > ohci_hcd > OHCI 1.0, NO legacy support registers > control 0x683 RWE RWC HCFS=operational CBSR=3 > cmdstatus 0x00006 SOC=0 BLF CLF > intrstatus 0x00000020 FNO > intrenable 0x8000005e MIE RHSC UE RD SF WDH > ed_controlhead 05817050 > ed_bulkhead 058170f0 > hcca frame 0xaac1 > fmintvl 0xa7782edf FIT FSMPS=0xa778 FI=0x2edf > fmremaining 0x8000238a FRT FR=0x238a > periodicstart 0x2a2f > lsthresh 0x0700 > hub poll timer off > roothub.a 01000206 POTPGT=1 NPS NDP=6(6) > roothub.b 00000000 PPCM=0000 DR=0000 > roothub.status 00008000 DRWE > roothub.portstatus [0] 0x00000103 PPS PES CCS > roothub.portstatus [1] 0x00000103 PPS PES CCS > roothub.portstatus [2] 0x00000100 PPS > roothub.portstatus [3] 0x00000100 PPS > roothub.portstatus [4] 0x00000100 PPS > roothub.portstatus [5] 0x00000100 PPS At first glance this looks normal. Here's something else you can try as well. Make sure CONFIG_USB_MON is enabled, and record a usbmon trace for the bus with the device that causes the hang. Instructions are in the kernel source file Documentation/usb/usbmon.txt. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
