#8894 HIGH Not Tri: Synaptics touchpad takes two seconds to wake up after resume

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#8894: Synaptics touchpad takes two seconds to wake up after resume
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     Reporter:  wad       |        Owner:  dsaxena       
         Type:  defect    |       Status:  new           
     Priority:  high      |    Milestone:  Not Triaged   
    Component:  kernel    |      Version:  not specified 
   Resolution:            |     Keywords:  CL1-A touchpad
  Next_action:  diagnose  |   Spec_stage:  unknown       
    Blockedby:            |     Blocking:                
Spec_reviewer:            |     Verified:  0             
Spec_reviewed:  0         |  
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Comment(by dsaxena):

 Quick skim of the serio/i8042/mousedev codebase shows that the
 suspend/resume path is pretty complicated. We need need to suspend the
 touch pad driver, the serio driver, i8402 driver, the mousedev driver, the
 input layer,  and then resume them all and in the process we are doing a
 full i8042 device reset and self-test.

 Wad, can you add no_console_suspend to your kernel command line? I don't
 know that we'll get anymore useful output but might as well try.

 What we need to do is add a bunch of simple printk() calls to the resume
 path to trace where we're spending most of our time. If the printk()
 throws the timing off, we can just have timestamp buffer we dump after
 we've fully resumed. We can also try a real profiling tool (lttng,
 systemtap, ftrace) but the ramp up time there is much greater.

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Ticket URL: <http://dev.laptop.org/ticket/8894#comment:3>
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