Why Wake Up on USB Activity?

One thing I've never understood is why Macs wake up from sleep on USB activity. Why is that?
Gary Morrison wrote on :

One thing I've never understood is why Macs wake up from sleep on USB activity. Why is that?

That seems to complicate things for no useful reason. Is there any way to turn off that feature, and only wake up when I open the lid (on a PowerBook) or hit a key on the keyboard?

Richard Maine replied on :

Gary Morrison mr88cet@redacted.invalid wrote:

One thing I've never understood is why Macs wake up from sleep on USB activity. Why is that?

That seems to complicate things for no useful reason. Is there any way to turn off that feature, and only wake up when I open the lid (on a PowerBook) or hit a key on the keyboard?

Well, except for laptops, the keyboard is a USB device (or BlueTooth), so there is a very concrete reason for the "complication". Even for laptops, it is common to have a USB keyoard connected. That's how I used to use my powerBook except when I was travelling. So you would certainly want at least the option.

As for turning the option off, I just checked and don't off-hand see a way to do it on this iMac. But I suppose it is at least concievable that the available options might vary depending on the model. I'd suggest checking the enery saver system preferences. That's where other simillar things are. It probably isn't there, but I suggest it just in case it happens to be for laptops (which I don't have one of at hand to check with).

Fred McKenzie replied on :

In article 46e37145$0$10467$4c368faf@redacted.invalid, Gary Morrison mr88cet@redacted.invalid wrote:

One thing I've never understood is why Macs wake up from sleep on USB activity.

Gary-

Certainly it needs to respond to keyboard activity as Richard suggested, but that shouldn't apply to a closed PowerBook.

What about responding to an incoming Fax from the Apple USB modem? Even the built-in modems of recent PowerBooks are probably using USB.

Fred

Richard Maine replied on :

Fred McKenzie fmmck@redacted.invalid wrote:

In article 46e37145$0$10467$4c368faf@redacted.invalid, Gary Morrison mr88cet@redacted.invalid wrote:

One thing I've never understood is why Macs wake up from sleep on USB activity.

Certainly it needs to respond to keyboard activity as Richard suggested, but that shouldn't apply to a closed PowerBook.

I don't have a powerbook any more. (That was a work machine, and I retired a few months ago). But my powerbook woke from sleep from external keyboard activity with the cover closed. In fact, that was how you got it to use an external monitor and turn off the built-in one. The procedure was

  1. Power on and boot as normal.
  2. Close lid to put it to sleep.
  3. Hit a key on the external keyboard to wake it.

You then had the powerbook using the external keyboard and monitor, which was the way I normally used it when at my desk.

Gary Morrison replied on :

Fred McKenzie wrote:

Certainly it needs to respond to keyboard activity as Richard suggested, but that shouldn't apply to a closed PowerBook.

I didn't realize that they hooked the keyboard in through USB. Curious...

I can't find any such options in the Power Saver or other System-Preferences panels.

What about responding to an incoming Fax from the Apple USB modem? Even the built-in modems of recent PowerBooks are probably using USB.

For my particular usage at least, that's not of much concern.

Jolly Roger replied on :

On 2007-09-09 20:15:39 -0500, Gary Morrison mr88cet@redacted.invalid said:

Fred McKenzie wrote:

Certainly it needs to respond to keyboard activity as Richard suggested, but that shouldn't apply to a closed PowerBook.

I didn't realize that they hooked the keyboard in through USB. Curious...

Why is that curious? Most keyboards these days are USB.

John C. Randolph replied on :

On 2007-09-08 21:07:40 -0700, Gary Morrison mr88cet@redacted.invalid said:

One thing I've never understood is why Macs wake up from sleep on USB activity. Why is that?

That seems to complicate things for no useful reason. Is there any way to turn off that feature, and only wake up when I open the lid (on a PowerBook) or hit a key on the keyboard?

The machine has to wake up to check what the USB event was.

-jcr