[haiku-bugs] Re: [Haiku] #6727: Asus A7N8X-X: USB mouse CPU drain...

  • From: "Luposian" <trac@xxxxxxxxxxxx>
  • Date: Tue, 09 Nov 2010 21:05:53 -0000

#6727: Asus A7N8X-X: USB mouse CPU drain...
  Reporter:  Luposian   |        Owner:  nobody
      Type:  bug        |       Status:  new
  Priority:  normal     |    Milestone:  R1
 Component:  - General  |      Version:  R1/alpha2
Resolution:             |     Keywords:
Blocked By:             |  Has a Patch:  0
  Platform:  x86        |     Blocking:

Comment (by Luposian):

 I've noticed that if I use a 3rd party USB 2.0 card (Belkin, I believe),
 on my Pentium II system in Haiku, my CPU usage drops significantly
 whenever I move the mouse.  In other words, if CPU usage is at 50%
 normally (using onboard USB), it drops to 25% or less, when plugged into
 the card.  I assumed this meant that a certain onboard chipset (that
 handles USB) simply wasn't being properly supported, hence the CPU

 Concerning a mouse/trackball updating (sending reports?), how could a
 device send 1 report after a 10px (pixels, right?) move of the mouse
 pointer?  Wouldn't that look like a single jump of 10px onscreen?
 Shouldn't the device simply stream the movement data as the mouse is being

 If you could explain (in accurate, but simplified terms) how the Haiku HID
 driver and a given USB mouse/trackball communicate, that would help me
 understand things a bit better.

 My thinking is that the HID driver simply asks "any data?" every few
 milliseconds or whatever.  The device simply sends what data it had, but
 only when the mouse is moved or a button pressed/held, etc.

 Is this how Haiku and a device does things or... ?

Ticket URL: <http://dev.haiku-os.org/ticket/6727#comment:5>
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