Hi, I am trying to use a USB modem for connecting to internet. On one system (kernel version 3.0-ARCH - arch linux), the modem work just fine. When I plug in the modem I see the following in dmesg output: [ 531.663476] usb 2-1.3: new full speed USB device number 6 using ehci_hcd [ 531.729928] usb 2-1.3: device descriptor read/64, error -32 [ 531.932595] ehci_hcd 0000:00:1a.0: BAR 0: set to [mem 0xe9670000-0xe96703ff] (PCI address [0xe9670000-0xe96703ff]) [ 531.932616] ehci_hcd 0000:00:1a.0: restoring config space at offset 0xf (was 0x100, writing 0x10b) [ 531.932637] ehci_hcd 0000:00:1a.0: restoring config space at offset 0x1 (was 0x2900000, writing 0x2900002) [ 531.932666] ehci_hcd 0000:00:1a.0: PME# disabled [ 531.932676] ehci_hcd 0000:00:1a.0: PCI INT A -> GSI 16 (level, low) -> IRQ 16 [ 531.932681] ehci_hcd 0000:00:1a.0: setting latency timer to 64 [ 532.108143] usbcore: registered new interface driver uas [ 532.116601] Initializing USB Mass Storage driver... [ 532.116803] scsi6 : usb-storage 2-1.3:1.0 [ 532.116991] usbcore: registered new interface driver usb-storage [ 532.116996] USB Mass Storage support registered. [ 533.114481] scsi 6:0:0:0: CD-ROM BSNL Mass Storage CD 7.00 PQ: 0 ANSI: 2 [ 533.130373] sr1: scsi3-mmc drive: 0x/0x caddy [ 533.130601] usb 2-1.3: USB disconnect, device number 6 [ 533.130673] sr 6:0:0:0: Attached scsi CD-ROM sr1 [ 533.130792] sr 6:0:0:0: Attached scsi generic sg2 type 5 [ 533.735044] usb 2-1.3: new full speed USB device number 7 using ehci_hcd [ 537.352578] usb 2-1.3: USB disconnect, device number 7 [ 539.324280] usb 2-1.3: new full speed USB device number 8 using ehci_hcd [ 539.390731] usb 2-1.3: device descriptor read/64, error -32 [ 539.580249] scsi7 : usb-storage 2-1.3:1.2 [ 539.694350] cdc_acm 2-1.3:1.0: This device cannot do calls on its own. It is not a modem. [ 539.694376] cdc_acm 2-1.3:1.0: ttyACM0: USB ACM device [ 539.694943] usbcore: registered new interface driver cdc_acm [ 539.694947] cdc_acm: USB Abstract Control Model driver for USB modems and ISDN adapters [ 540.663978] scsi 7:0:0:0: CD-ROM BSNL Mass Storage CD 7.00 PQ: 0 ANSI: 2 [ 540.667412] sr1: scsi-1 drive [ 540.667608] sr 7:0:0:0: Attached scsi CD-ROM sr1 [ 540.667719] sr 7:0:0:0: Attached scsi generic sg2 type 5 [ 540.671445] scsi 7:0:0:1: Direct-Access BSNL Mass Storage SD 7.00 PQ: 0 ANSI: 0 CCS [ 540.671593] sd 7:0:0:1: Attached scsi generic sg3 type 0 [ 540.695526] sd 7:0:0:1: [sdb] Attached SCSI removable disk [ 545.837797] ehci_hcd 0000:00:1a.0: PCI INT A disabled [ 545.837848] ehci_hcd 0000:00:1a.0: PME# enabled And further, I can see a modem device that has been created: $ ls -al /dev/ttyACM0 crw-rw---- 1 root uucp 166, 0 Oct 23 10:32 /dev/ttyACM0 The uname -a output for above laptop is as follows: $ uname -a Linux ncdl 3.0-ARCH #1 SMP PREEMPT Wed Oct 19 12:14:48 UTC 2011 i686 Intel(R) Core(TM) i7 CPU M 620 @ 2.67GHz GenuineIntel GNU/Linux That's the good story. On another laptop, however, with the exact same configuration (i.e. same Arch Linux OS - updated to latest packages, same version of kernel, same usb_modeswitch, etc.), I am unable to get the modem working. Relevant dmesg output on the erring system is as follows: [ 110.733357] usb 3-4: new full speed USB device number 2 using ohci_hcd [ 111.008963] usbcore: registered new interface driver uas [ 111.013807] Initializing USB Mass Storage driver... [ 111.014002] scsi6 : usb-storage 3-4:1.0 [ 111.014584] usbcore: registered new interface driver usb-storage [ 111.014589] USB Mass Storage support registered. [ 115.874991] usb 3-4: USB disconnect, device number 2 [ 116.603349] usb 3-4: new full speed USB device number 3 using ohci_hcd [ 120.318220] usb 3-4: USB disconnect, device number 3 [ 122.470016] usb 3-4: new full speed USB device number 4 using ohci_hcd [ 122.674921] scsi7 : usb-storage 3-4:1.0 [ 127.609811] usb 3-4: USB disconnect, device number 4 [ 128.340027] usb 3-4: new full speed USB device number 5 using ohci_hcd [ 132.054897] usb 3-4: USB disconnect, device number 5 [ 134.206682] usb 3-4: new full speed USB device number 6 using ohci_hcd [ 134.411569] scsi8 : usb-storage 3-4:1.0 [ 139.348770] usb 3-4: USB disconnect, device number 6 [ 140.076697] usb 3-4: new full speed USB device number 7 using ohci_hcd [ 143.791527] usb 3-4: USB disconnect, device number 7 [ 145.943349] usb 3-4: new full speed USB device number 8 using ohci_hcd [ 146.148256] scsi9 : usb-storage 3-4:1.0 [ 151.084257] usb 3-4: USB disconnect, device number 8 [ 151.823349] usb 3-4: new full speed USB device number 9 using ohci_hcd [ 155.538217] usb 3-4: USB disconnect, device number 9 [ 157.690014] usb 3-4: new full speed USB device number 10 using ohci_hcd [ 157.894929] scsi10 : usb-storage 3-4:1.0 [ 162.832292] usb 3-4: USB disconnect, device number 10 [ 163.600022] usb 3-4: new full speed USB device number 11 using ohci_hcd [ 167.314879] usb 3-4: USB disconnect, device number 11 [ 169.466682] usb 3-4: new full speed USB device number 12 using ohci_hcd [ 169.671591] scsi11 : usb-storage 3-4:1.0 [ 174.610718] usb 3-4: USB disconnect, device number 12 [ 175.340022] usb 3-4: new full speed USB device number 13 using ohci_hcd [ 179.055539] usb 3-4: USB disconnect, device number 13 [ 181.210010] usb 3-4: new full speed USB device number 14 using ohci_hcd [ 181.415588] scsi12 : usb-storage 3-4:1.0 This keeps on happening till I unplug this device. The uname command output on this system is as follows: $ uname -a Linux ncdl-acer 3.0-ARCH #1 SMP PREEMPT Wed Oct 19 12:14:48 UTC 2011 i686 AMD Athlon(tm) 64 X2 Dual-Core Processor TK-55 AuthenticAMD GNU/Linux I am attaching the full dmesg output from the erring system if that is of any help. TIA
Attachment:
dmesg-on-system-with-fault
Description: Binary data
