#5299 NORM Never A: plugging in USB device causes screen trouble

[Zarro Boogs per Child]

#5299: plugging in USB device causes screen trouble
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 Reporter:  AlbertCahalan  |       Owner:  wad           
     Type:  defect         |      Status:  new           
 Priority:  normal         |   Milestone:  Never Assigned
Component:  hardware       |     Version:                
 Keywords:                 |    Verified:  0             
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 This is B4 hardware. I was at the Linux kernel console, with sugar still
 fully running.

 On the left, I had a USB-to-Ethernet device. (Belkin, 10/100, pegasus
 driver)

 On the lower right, I had an optical mouse. (Apple "Pro Mouse", black with
 body as button)

 Into the upper right I added a USB key. (SanDisk U3 Cruzer Micro, 1 GB)

 Instantly, a large portion of the screen went black. The black areas
 appeared to be several overlapping rectangles, covering perhaps 1/3 of the
 screen area. As messages from the automounter and/or drivers scrolled,
 they appeared to go under the black areas. Touching the keyboard caused
 instant full recovery.

 Random guess: electrical glitch messing up a video-related chip.

 I was able to reproduce it with a second mouse in place of the USB key. I
 was not able to reproduce it with either the USB key or second mouse after
 the initial time. It seems that a USB device is only good for one glitch.
 Perhaps USB devices store a bit of charge.

 This may be related to the bug involving characters that disappear from
 the console, and may be related to the bug involving the black square
 appearing in X when under memory pressure.

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Ticket URL: <http://dev.laptop.org/ticket/5299>
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