On Wed, 12 Dec 2012, Robert Hancock wrote: > On 12/11/2012 02:37 PM, Alan Stern wrote: > > On Tue, 11 Dec 2012, prasannatsmkumar wrote: > > > >> Hi All, > >> > >> I connected an Android phone using USB cable to my machine running > >> Linux (Linux 3.0, 3.2, 3.5). Mounted the SD card in phone in system > >> (phone is just a pass through I guess). When I choose "Safely Remove" > >> option in nautilus file manager (gnome's default file manager) I got > >> an error saying > >> > >> "Error detaching: helper exited with exit code 1: Detaching device /dev/sdb > >> USB device: /sys/devices/pci0000:00/0000:00:1d.7/usb1/1-5) > >> SYNCHRONIZE CACHE: OK > >> STOP UNIT: FAILED: No such file or directory" > > > > STOP UNIT means spin down the disk or eject the disc. Since your phone > > doesn't have a disk drive or an optical disc, no wonder this step > > failed. > > The reason it's likely doing a STOP UNIT on USB storage devices is that > this is preferable for at least USB-connected HDs (at least where the > USB to SATA, etc. converter bothers to implement the translation). For > many drives, it's better for the disk's lifespan to power it down > normally (as it would be if it was in a machine that was being shut > down) so it can unload its heads in a controlled fashion, rather than > just cutting the power on the running disk and causing an emergency head > retract. > > Some types of devices may not support that command or may not do > anything useful with it, but "No such file or directory" seems a strange > error to run into. That's the error code returned by the USB stack when a request is cancelled synchronously. But it is intended for internal kernel use only; it should not appear at the userspace level. Without knowing the details of what the program did, it's hard to tell how that code got there. 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
