On Mon, Oct 24, 2011 at 11:21:30AM +0530, OBD wrote: > On 23 October 2011 21:41, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote: > > > > The type of system doesn't matter; what matters is the USB hardware. > > The usbmon trace shows that the modem gets disconnected whenever the > > OHCI controller on the AMD system issues a reset. This could be the > > fault of the modem or of the controller. > > > > Do any other full-speed devices work on this system? > > Actually, a few USB disk drives have been connected to this system in > the past (to the same USB port as well). Even now one USB Disk Drive > is connected. I am not sure if it is full speed or not. How does one > check that? > > Further I tried connecting another USB modem to the same system. The > dmesg log when I connected the modem is as follows: > > > > [82869.475111] hub 2-0:1.0: unable to enumerate USB device on port 1 > [82869.791769] hub 4-0:1.0: unable to enumerate USB device on port 1 > [82870.138438] hub 2-0:1.0: unable to enumerate USB device on port 1 > [82870.408438] hub 2-0:1.0: unable to enumerate USB device on port 1 > [82870.668437] hub 2-0:1.0: unable to enumerate USB device on port 1 > [82870.988871] hub 4-0:1.0: unable to enumerate USB device on port 1 > [82871.215110] hub 2-0:1.0: unable to enumerate USB device on port 1 > [82872.081784] hub 2-0:1.0: unable to enumerate USB device on port 1 > [82925.208420] usb 3-2: new full speed USB device number 102 using ohci_hcd > [82925.408229] scsi183 : usb-storage 3-2:1.0 > [82926.416938] scsi 183:0:0:0: CD-ROM ZTE USB Storage > FFF1 2.31 PQ: 0 ANSI: 2 > [82926.450873] sr1: scsi-1 drive > [82926.451482] sr 183:0:0:0: Attached scsi CD-ROM sr1 > [82926.451777] sr 183:0:0:0: Attached scsi generic sg3 type 5 > [82926.458379] scsi 183:0:0:1: Direct-Access ZTE USB Storage > FFF1 2.31 PQ: 0 ANSI: 2 > [82926.459088] sd 183:0:0:1: Attached scsi generic sg4 type 0 > [82926.514865] sd 183:0:0:1: [sdc] Attached SCSI removable disk > [82926.799271] BUG: unable to handle kernel NULL pointer dereference at 00000004 > [82926.800459] IP: [<f8534f07>] sd_revalidate_disk+0x27/0x1cb0 [sd_mod] Ick, this bug has been fixed already, I suggest you update your kernel to the latest version. Also, try this without the nvidia driver running, we can't support your kernel when you use it, sorry. greg k-h -- 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
