Messages in this thread | | | Date | Fri, 2 Jan 2009 00:03:43 +0800 | From | Yan Li <> | Subject | Enable CONFIG_USB_SUSPEND by default or some mobile HD can't be unplugged safely |
| |
Hello List,
By default CONFIG_USB_SUSPEND is not enabled and today I got bite by this when I got a new WDC My Book hard drive. I have no way to unplug it safely, according to it's manual, with a kernel that doesn't have CONFIG_USB_SUSPEND=y.
On it's manual read "you should unplug and remove the device only when the light is off." On Linux unmounting it won't turn it's light off and I can feel it's motor is still running. The only way to unplug it properly on a Linux system, as to my knowledge, is to echo `suspend' to `/sys/bus/usb/devices/$DEV/power/level'. And one has to have CONFIG_USB_SUSPEND=y to do this.
On Windows and Mac OS, `safely remove this device' function effectly turns it into `suspend' mode, and it's light off.
I'm new in this field and I understood people's concern on enabling autosuspend. As to my understanding, `enabling suspend' and `enabling autosuspend' should be controlled by two different knobs. I did a quick search in LKML and haven't found specific oppose to enable USB suspend by default, and Debian has started shipping a kernel with it turned on since 2.6.26.
Perhaps we should consider turning it on by default? Thanks!
-- Li, Yan
| |