[Adding CC's, since this is a CPU power management issue just as much as a USB issue.] On Fri, 18 Sep 2009, Jan Holst Jensen wrote: > Hi. > > I recently had severe problems with a new PC. When attaching an external > USB disk I would see USB resets once in a while in /var/log/messages and > after another while the disk would disconnect and data would be lost. > Like this > > Sep 13 13:30:56 rumleskaft kernel: [164642.760290] usb 1-5: reset high > speed USB device using ehci_hcd and address 3 > [repeated a number of times] > Sep 13 13:31:17 rumleskaft kernel: [164663.430421] sd 2:0:0:0: Device > offlined - not ready after error recovery > Sep 13 13:31:17 rumleskaft kernel: [164663.430459] sd 2:0:0:0: [sdb] > Result: hostbyte=DID_ABORT driverbyte=DRIVER_OK,SUGGEST_OK > Sep 13 13:31:17 rumleskaft kernel: [164663.436193] usb 1-5: USB > disconnect, address 3 > Sep 13 13:31:17 rumleskaft kernel: [164663.436446] sd 2:0:0:0: [sdb] > Result: hostbyte=DID_NO_CONNECT driverbyte=DRIVER_OK,SUGGEST_OK > Sep 13 13:31:17 rumleskaft kernel: [164663.437711] lost page write due > to I/O error on sdb2 > Sep 13 13:31:17 rumleskaft kernel: [164663.454184] lost page write due > to I/O error on sdb2 > > On my machine I found that disabling CPU C-states and forcing "GV3 only" > solved the problem completely. So in some cases it would seem that CPU > power management is causing timing issues (?). Can this be fixed in the > USB driver layer or does it take cooperation from the kernel's CPU power > management - or perhaps a combination of both ? > > You can read more details about my issue at > > http://www.fit-pc2.com/forum/viewtopic.php?f=26&t=851 > > Cheers > -- Jan Holst Jensen, Denmark For what it's worth, I haven't heard of anything like this before and I have no idea what the answers are. My guess is that a hardware bug is responsible for the misbehavior while in higher C states. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html