Re: [linux-usb-devel] error to be returned while suspended
From: Alan Stern
Date: Thu Oct 05 2006 - 17:47:10 EST
On Thu, 5 Oct 2006, Oliver Neukum wrote:
> I have a few observations, but no solution either:
> - if root tells a device to suspend, it shall do so
Probably everyone will agree on that.
> - the issues of manual & automatic suspend and remote wakeup are orthogonal
Except for the fact that remote wakeup kicks in only when a device is
suspended.
> - there should be a common API for all devices
It would be nice, wouldn't it? But we _already_ have several vastly
different power-management APIs. Consider for example DPMI and IDE
spindown.
> - there's no direct connection between power save and open()
Why shouldn't a device always be put into a power-saving mode whenever it
isn't open? Agreed, you might want to reduce its power usage at times
even when it is open...
> The question when a device is in use is far from trivial.
Yes. It has to be decided by each individual driver. For simple
character-oriented devices, "open" is a good first start.
Alan Stern
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/