I'm not really expecting a solution to this, just ranting/reporting an oddity. It confirms my general distrust/hatred of USB in general! :-)
I have a little Acer Aspire netbook that I use (as I am now) when away from home, it runs xubuntu 11.10 (though I'm fairly certain I saw the same problem with previous versions of xubuntu).
I use a Genius/Kye Traveller 350 mouse with it rather than the horrible touchpad. This works beautifully as it's actually a trackball rather than a mouse and has a scrollwheel and a fourth button that I have programmed as a double click of button one - bliss! :-)
However after a random amount of time the Genius mouse stops working, since this is quite a long time (like hours rather than minutes) it doesn't often worry me too much as I don't spend hours on my laptop. Tonight though I decided to have a play and see if I could work out why it stops working (as the netbook had been left turned on and the mouse had, as usual, stopped working).
I have the mouse plugged into the left hand side of the netbook where there are two USB ports as I usually use it left handed (even though I'm actually right handed). Since it had died just now I unplugged it and plugged it back in a couple of times, nothing, dmesg/syslog shows nothing, it's as if the mouse doesn't exist. If I reboot though it will work with no problem.
Then I tried plugging it into the USB port on the RHS of the netbbok, and it works! It's still working. I can plug/unplug it repeatedly and it works every time. If I plug it in to the LHS ports there's still nothing happening though. Other devices (e.g. memory sticks) plugged into the LHS USB ports work perfectly though. It's just the mouse that won't work in the LHS ports (until I reboot!).
Wierd! I think USB is a creation of arcane beings.
If you grep the kernel logs or dmesg for the USB device it appears as after it has disconnected you should see some reason
I am guessing the USB controller has blacklisted it for doing something strange. I think I have seen this happen before where the controller blacklists devices until the next reboot so unplugging and re-plugging won't work. The reason it works on the other sides ports is probably that you have more than one instance of the controller and the mouse hasn't been blacklisted on the other one yet.
I suspect if you leave it there for long enough the same thing will happen on that side.
I would suggest that if you look back for the disconnection event in the logs then you might get somewhere towards finding a reason.
Also when you plug it into the ports and it doesn't work is there any indication that it is powered up (say the equivalent of the LED under an optical mouse lighting up ?)
I think USB does a pretty good job as a generic low(ish) speed bus...Given the variety of devices it ended up supporting we could have ended up with something quite a bit more nasty or proprietary.
Physical issues I have with the connectors aside I think the implementation is ok, specialist interfaces can often do a better job but only for a fraction of devices USB has supported.
On Mon, Apr 02, 2012 at 06:44:31PM +0100, Wayne Stallwood wrote:
If you grep the kernel logs or dmesg for the USB device it appears as after it has disconnected you should see some reason
OK, I'll look.
I am guessing the USB controller has blacklisted it for doing something strange. I think I have seen this happen before where the controller blacklists devices until the next reboot so unplugging and re-plugging won't work. The reason it works on the other sides ports is probably that you have more than one instance of the controller and the mouse hasn't been blacklisted on the other one yet.
I suspect if you leave it there for long enough the same thing will happen on that side.
You're right! It's tomorrow night now and the mouse doesn't work in the RHS USB socket.
I would suggest that if you look back for the disconnection event in the logs then you might get somewhere towards finding a reason.
Also when you plug it into the ports and it doesn't work is there any indication that it is powered up (say the equivalent of the LED under an optical mouse lighting up ?)
I think USB does a pretty good job as a generic low(ish) speed bus...Given the variety of devices it ended up supporting we could have ended up with something quite a bit more nasty or proprietary.
Physical issues I have with the connectors aside I think the implementation is ok, specialist interfaces can often do a better job but only for a fraction of devices USB has supported.
Yes, OK, USB isn't as bad as I make out.
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Chris Green -
Wayne Stallwood