Ticket #474 (closed defect: fixed)

Opened 8 years ago

Last modified 7 years ago

Touchpad might lockup on some systems

Reported by: mfoster Owned by: wad
Priority: high Milestone: BTest-3
Component: hardware Version:
Keywords: relnote Cc: warp@…
Action Needed: Verified: yes
Deployments affected: Blocked By:
Blocking:

Description (last modified by jg) (diff)

Due to the same ESD sensitivity documented in Trac #473, it is possible that the touchpad assembly might lockup and not generate cursor movement. If this occurs, the temporary workaround is to power the unit off and on again to reset the er rors induced when static buildup discharges through the touchpad's controller ASIC.

This is a very high priority fix for the B2 systems - details on the fix are noted in Trac #473.

Change History

Changed 8 years ago by mfoster

  • status changed from new to assigned

In addition to the fixes in Trac #473, an additional change will be made to the touchpad's sensor assembly. Currently, an internal ground layer is present in the pad, but this is improperly implemented by the touchpad manufacturer. In B2 systems, a separate metal plate will underlie the touchpad assembly to provide a direct ground path to chassis ground.

Changed 8 years ago by jg

  • keywords relnote added
  • description modified (diff)

Changed 8 years ago by 90030501

Frank:Add grounding on Hinge position and TP. We will get sample on 12/10/06'

Changed 8 years ago by 90030501

Frank: Sorry we can not get sample on time. Cause we stop some tooling modify for 12/03/06' meeting. We will get sample on 12/25/06'.

Changed 8 years ago by jg

  • owner changed from mfoster to wad
  • status changed from assigned to new
  • component changed from mechanical to hardware
  • milestone changed from BTest-2 to BTest-3

I've had my touchpad lock up on my B2 system once: it was not apparently an EC problem, as a reboot cleared the problem (no battery removal was required). Performing a recalibrate operation did not help (maybe we should suggest to ALPS that recalibrate also try to reset the touch pad chip if possible).

If I figure out how to reproduce this I'll update this note.

Changed 8 years ago by wad

  • priority changed from blocker to high
  • status changed from new to assigned

Changed 7 years ago by warp

On jg's lockup. It is possible that this may have been the (now fixed) race condition in the GS to PT switch.

That would have left the touchpad in PT mode, with no indication that this was the case.

Reproduction would involve a build prior to the fix entering the kernel, and a very brief contact with a fingernail or other object that would have been detected as a stylus.

My inclination is to close this and open a new bug if it shows up again on a kernel with the GS to PT switch race fix present. Jim?

Changed 7 years ago by jg

  • cc warp@… added

My report should be separated out; it is clearly different than the ESD error.

So far, so good on B2; I've not heard of any EC lockups (lockups requiring removing power from the system to clear.

Changed 7 years ago by jg

  • status changed from assigned to closed
  • resolution set to fixed

I think we would have heard of problems by now; it appears that we are through the ESD problems we had in B1, so I'm closing this out.

We do need to do ESD testing at B3 bringup, of course, in case something sneaks in.

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