On Tue, 30 Sep 2014, Benjamin Tissoires wrote: > When events occurs while no one is listening to the node (hid->open == 0 > and usb_kill_urb() called) some events are still stacked somewhere in > the USB (kernel or device?) stack. When the node gets reopened, these > events are drained, and this results in spurious touch down/up, or mouse > button clicks. > > The problem was spotted with touchscreens in fdo bug #81781 [1], but it > actually occurs with any mouse using hid-generic or touchscreen. > > A way to reproduce it is to call: > > $ xinput disable 9 ; sleep 5 ; xinput enable 9 > > With 9 being the device ID for the touchscreen/mouse. During the "sleep", > produce some touch events or click events. When "xinput enable" is called, > at least one click is generated. > > This patch tries to fix this by draining the queue for 50 msec and > during this time frame, not forwarding these old events to the hid layer. > > Hans completed the explanation: > """ > Devices like mice (basically any hid device) will have a fifo > on the device side, when we stop submitting urbs to get hid reports from > it, that fifo will fill up, and when we resume we will get whatever > is there in that fifo. > """ > > [1] https://bugs.freedesktop.org/show_bug.cgi?id=81781 > > Signed-off-by: Benjamin Tissoires <benjamin.tissoi...@redhat.com> > --- > > OK, I know this is uggly, but I could not find a better way :(
I have been thinking about this quite a lot, but unfortunately wasn't able to come up with anything better either, so I am queuing this now. Thanks. -- Jiri Kosina SUSE Labs -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
