Comment 16 for bug 690798

Unfortunately the fix seems to be incomplete for me.

$ cat /proc/version_signature
Ubuntu 2.6.32-28.55-generic 2.6.32.27+drm33.12
$ uname -a
Linux ubuntu 2.6.32-28-generic #55-Ubuntu SMP Mon Jan 10 21:21:01 UTC 2011 i686 GNU/Linux

Reverting the commit 55b5b5448771f964776a716227afd3ddef2c860e does help, but it appears that another regression has appeared in the meantime. After about 18h I start getting this error from digitemp (I am calling it from cron once every 15min)

Error 5: DS2480B Adapter Not Detected
Error 10: Read COM Failed
Error 10: Read COM Failed
Error 10: Read COM Failed
Error 10: Read COM Failed
Error 10: Read COM Failed
Error 10: Read COM Failed
Error 10: Read COM Failed
Error 10: Read COM Failed
Error 10: Read COM Failed

Once the system gets into this state, it persists until reboot.

I do not see this problem with 2.6.32-26-generic, patched so that 55b5b5448771f964776a716227afd3ddef2c860e is reverted.

lsusb still sees the device:
$ lsusb
Bus 005 Device 003: ID 046d:c03d Logitech, Inc. M-BT96a Pilot Optical Mouse
Bus 005 Device 002: ID 0403:6001 Future Technology Devices International, Ltd FT232 USB-Serial (UART) IC
Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 002 Device 003: ID 413c:2003 Dell Computer Corp. Keyboard
Bus 002 Device 002: ID 03f0:3611 Hewlett-Packard PSC 2410 PhotoSmart
Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

$ sudo lsusb -v -d 0403:6001

Bus 005 Device 002: ID 0403:6001 Future Technology Devices International, Ltd FT232 USB-Serial (UART) IC
Device Descriptor:
  bLength 18
  bDescriptorType 1
  bcdUSB 2.00
  bDeviceClass 0 (Defined at Interface level)
  bDeviceSubClass 0
  bDeviceProtocol 0
  bMaxPacketSize0 8
  idVendor 0x0403 Future Technology Devices International, Ltd
  idProduct 0x6001 FT232 USB-Serial (UART) IC
  bcdDevice 6.00
  iManufacturer 1 FTDI
  iProduct 2 FT232R USB UART
  iSerial 3 A900a3DX
  bNumConfigurations 1
  Configuration Descriptor:
    bLength 9
    bDescriptorType 2
    wTotalLength 32
    bNumInterfaces 1
    bConfigurationValue 1
    iConfiguration 0
    bmAttributes 0xa0
      (Bus Powered)
      Remote Wakeup
    MaxPower 90mA
    Interface Descriptor:
      bLength 9
      bDescriptorType 4
      bInterfaceNumber 0
      bAlternateSetting 0
      bNumEndpoints 2
      bInterfaceClass 255 Vendor Specific Class
      bInterfaceSubClass 255 Vendor Specific Subclass
      bInterfaceProtocol 255 Vendor Specific Protocol
      iInterface 2 FT232R USB UART
      Endpoint Descriptor:
        bLength 7
        bDescriptorType 5
        bEndpointAddress 0x81 EP 1 IN
        bmAttributes 2
          Transfer Type Bulk
          Synch Type None
          Usage Type Data
        wMaxPacketSize 0x0040 1x 64 bytes
        bInterval 0
      Endpoint Descriptor:
        bLength 7
        bDescriptorType 5
        bEndpointAddress 0x02 EP 2 OUT
        bmAttributes 2
          Transfer Type Bulk
          Synch Type None
          Usage Type Data
        wMaxPacketSize 0x0040 1x 64 bytes
        bInterval 0
Device Status: 0x0000
  (Bus Powered)

The device node seems to have normal permissions
$ ls -l /dev/ttyUSB0
0 crw-rw---- 1 root dialout 188, 0 2011-01-29 20:50 /dev/ttyUSB0

stracing with the device in this state shows digitemp (3.5.0ds1-1ubuntu1) trying to select() a file descriptor (with the same arguments as in the working case,) and timing out. straces for both kernels are attached.

If I unplug and replug the device I see this in syslog:

[71833.368048] usb 5-1: USB disconnect, address 2
[71833.368231] ftdi_sio ttyUSB0: FTDI USB Serial Device converter now disconnected from ttyUSB0
[71833.368252] ftdi_sio 5-1:1.0: device disconnected
[71837.328016] usb 5-1: new full speed USB device using uhci_hcd and address 4
[71837.526685] usb 5-1: configuration #1 chosen from 1 choice
[71837.534634] ftdi_sio 5-1:1.0: FTDI USB Serial Device converter detected
[71837.534671] usb 5-1: Detected FT232RL
[71837.534674] usb 5-1: Number of endpoints 2
[71837.534676] usb 5-1: Endpoint 1 MaxPacketSize 64
[71837.534679] usb 5-1: Endpoint 2 MaxPacketSize 64
[71837.534681] usb 5-1: Setting MaxPacketSize 64
[71837.535923] usb 5-1: FTDI USB Serial Device converter now attached to ttyUSB0

and the device is working again.