Ticket #895 (closed defect: fixed)

Opened 8 years ago

Last modified 8 years ago

Mouse and keyboard power is not a unique power rail

Reported by: rsmith Owned by: wad
Priority: blocker Milestone: BTest-3
Component: hardware Version:
Keywords: wad Cc: Arnold.Kao@…, Terry.su@…
Action Needed: Verified: yes
Deployments affected: Blocked By:


Mouse and Keyboard power are connected to +3.3V. However, so are the following devices:

  • GX VddIO and a few misc sub-systems.
  • PCI bus
  • Clock chip
  • CS 5536 VIO and a few other systems.
  • LPC bus
  • USB power
  • DCON 3.3V and EDID pullups
  • Several LEDs
  • AD1888

So from a STR power savings standpoint we need to turn off the +3.3V rail. But if we turn off that rail we will lose the ability to get wakeup events from mouse or keyboard. So mouse and keyboard need their own rail.

Also if we turn off the +3.3V rail to the DCON is that going to cause it problems with keeping the display up?

Change History

  Changed 8 years ago by jg

  • keywords wad added
  • milestone changed from Untriaged to BTest-3

  Changed 8 years ago by wad

  • owner changed from mlj to wad

Will modify and test. Await firmware support for suspend/resume for testing.

follow-up: ↓ 4   Changed 8 years ago by wad

  • status changed from new to assigned

in reply to: ↑ 3   Changed 8 years ago by gary

  • cc Arnold.Kao@…, Terry.su@… added

Replying to wad:We will use SUS_3.3V to separate a power source for PS2 touchpad and keyboard, but it will depend on how many power will taken by PS2 touchpad and keyboard, we need further analysis.

DCON 3.3V power rail is only for DCON receive Geode 3.3V TFT interface signal, therefor DCON can work properly without 3.3V in DCON self-reflash mode.

  Changed 8 years ago by wad

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

Gary's fix (moving it to SUS_3.3V) is accepted and will be included in the B3 build.

In the meantime, existing B2 units can be easily modified to fix this problem. Instructions are available at:  http://wiki.laptop.org/go/B2_Suspend_ECR

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