Re: USB mouse autosuspend
Alan Stern <[email protected]>
| Newsgroups | gmane.linux.usb.devel |
|---|---|
| Message-ID | <[email protected]> |
On Wed, 4 Jul 2007, Robert Marquardt wrote: > Jiri Kosina schrieb: > > > It could be that only the light goes on for a few seconds (Alan, are you > > sure that the power would not suffice?), but the mouse is not issuing any > > wakeup request. > > If a USB device suspends because te bus goes idle then it is allowed to > draw 2.5 mA if it is a 500 mA device and supports remote wakeup. All > others are only allowed considerably less. LEDs start at 10 mA (not the > cheap ones). So the LED going off means the device tries to behave. Robert is right and I was wrong. My memory sometimes plays tricks... The correct figures for suspended devices are 2.5 mA for high-powered wakeup devices and 0.5 mA for non-high-powered devices (like a mouse). > Definitely. i have a flagship Cherry keyboard here which needs seconds > if i send it some basic HID commands like reading the device strings > (under Windows). Does Windows ever actually suspend the keyboard at all? > Apple USB products tend to have better quality. They get tested > routinely to work with MacOS and Windows. Often enough they are quirky > to support Windows. > BTW keyboards with hubs are usually full-speed devices whereas other > keyboards are usually low-speed. Newer mice are also full-speed to be > attractive to gamers. Maybe the resume problem hides in that area. The keyboards I tested were full-speed. Jiri, I tested my laptop with the HP keyboard. The root hub behavior was just as peculiar as before. It was able to resume okay a few times and then it stopped working. That laptop is about 5 five years old and showing other signs of hardware failure. We shouldn't take this problem too seriously. Alan Stern ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ _______________________________________________ [email protected] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel