On Mon, 26 Apr 2010, Oliver Neukum wrote: > Am Montag, 26. April 2010 14:53:55 schrieb Gadiyar, Anand: > > Hi all, > > > > Did we lose the ability to manually suspend a USB device > > from v2.6.32 and later kernels? > > I am not sure the exact release is 2.6.32, but yes, that feature > has been lost. > > > I see the /sys/bus/usb/devices/.../power/level, but it looks > > like "auto" and "on" are the only supported values. > > The generic device model supports only "on" and "auto". > > > Is there a way to get back the old behavior? > > No. > > > (I run test cases that suspend/resume connected devices > > for a few thousand times (due to past bugs in our hardware), > > and I cannot figure out a way to do this now). > > Enable autosuspend, set the timeout to 0. Then run "lsusb" in a > loop with a minimal delay. It's also necessary to unbind the device's driver(s) or to unconfigure the device, unless the driver has autosuspend support. You don't need to run lsusb; you can alternatively write "on" and "auto" to the power/control (or power/level in older kernels) file. This won't query all the other USB devices on your system, the way lsusb does. 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
