Comment 117 for bug 952080
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#117 |
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a60fb26
(Get the code!)
Yes, the D+ (full/high speed) or D- line (low speed) remains at +5 V while the device is suspended.
Unplugging a device from the computer is not the only way to wake up a system via USB. Plugging in a device will also cause a wakeup, and in fact plugging/unplugging a device to any hub (not just the computer) will cause a wakeup. Furthermore some devices can issue wakeup requests on their own; typically a USB keyboard will wake up the system if you press one of the keys.
These ASUS systems wake up immediately when a device is connected, because the loss of power (the +5V line goes down during S3) is detected as an unplug. Plugging in a device while the system is asleep doesn't cause a wakeup because the plug-in event can't be detected when the +5V power is off. If the jumper were set to +5VSB then plugging in a device _would_ cause a wakeup.
> The fact that the working boards seem to have no +5V/+5VSB jumper could be a
> hint that it's bug in the electric circuit.
That's more or less what I've been saying ever since comment #45.