Ticket #2253 (new defect)

Opened 10 years ago

Last modified 10 years ago

Very high, silent beep when screen in horizontal mode (xrand -3)

Reported by: rhk Owned by: openmoko-devel
Priority: normal Milestone:
Component: unknown Version:
Severity: normal Keywords:
Cc: risto@…, testing@… Blocked By:
Blocking: Estimated Completion (week):
HasPatchForReview: no PatchReviewResult:
Reproducible:

Description

Om2008.12-om-gta02.rootfs.jffs2
and
Om2008.12-om-gta02.uImage.bin

Linux om-gta02 2.6.24 #1 PREEMPT Wed Dec 17 02:13:29 CST 2008 armv4tl unknown

ssh in and run DISPLAY=:0 xrandr -o 3 (or 1)
-> a very high (guess it's near the frequencies one can still hear..)

xrandr -o 0 (and 2) stops it.

Switching between -o 1 and -o 3 changes the frequency a little but it's still very high.

Will test with newer kernels as instructed by PaulFert? & DocScrutinizer? (#openmoko)

Change History

comment:1 Changed 10 years ago by rhk

PaulFert? & DocScrutinizer? helped me to figure out some details:

  • md5sum /dev/random doesn't effect
  • I'm 27, my ears should be OK but it shouldn't be too high for someone with normal hearing
  • pressing the phone or the sreen has no effect (except when touching the screen I hear a little lower beep, very silent, stops when I release)
  • illume-theme (dark) vs full white screen has no effect
  • backlight brightness has no effect
  • I can hear it furthen than where my hand reaches. The signal is very 'well focused' -> when the screen is pointing at me I can hear it, when I turn it a bit away it gets quieter
  • trying all 'mute' options in alsamixer had no effect
  • pluggin in the headphone (no alsa state changes, I'd guess) had no effect
  • filling my ears with beewax is a bad solution
  • running on battery only vs battery+usb has no effect
  • submerging in liquid copper or extra-virgin olive oil prevents me from hearing it and eventyally stops the beep too :)

I'm working on trying newer kernels...

comment:2 Changed 10 years ago by andy

Lol sounds like you're taking down a Terminator.

You should definitely try current andy-tracking, the problems with rotation are solved by Balaji there. What exactly is resonating I can't guess, typically it's PSU inductor but it's unclear why it would be audible.

comment:3 Changed 10 years ago by rhk

Ok, finally got -29 kernel installed from http://people.openmoko.org/andy/uImage-moredrivers-GTA02_andy-tracking-d1a9cf85c8608601.bin with modules from http://people.openmoko.org/andy/modules-GTA02_andy-tracking-d1a9cf85c8608601.tar.gz

This Terminator is a tough one :)

Newer kernel changed it so that no matter if I try -o 3 or -o 1 it makes the same very high beep and -o 0 and -0 2 stops it. It might be a little quieter than with the old kernel or it's just my ears getting destroyed slowly by the beep, making me insane :) No, it's really not THAT bad but I really wouldn't like to hear it when speaking on the phone.

md5sum /dev/random - no effect
pressing around the screen/phone - no effect

comment:4 Changed 10 years ago by wendy_hung

  • Cc testing@… added

we would like to know which hardware version you're using (open the front case, you'll see A5/A6 word at left bottom corner). The testing team doesn't happen with this problem while testing this, but maybe because we're using different HW version?

comment:5 Changed 10 years ago by andy

My guess is this problem belongs to the specific unit FWIW, likely something to do with total current on that device or something physical about a PMU inductor that makes it resonate.

When we change to landscape orientation the speed of the Glamo video unit changes and so does the total amount of current drawn, I guess the PMU is feeling that for some reason.

comment:6 Changed 10 years ago by rhk

I dont have a suitable screwdriver available at the moment but I'm quite sure that it's a A5 (date in the sticker: 20080621, S/N: 8A8602824 )

Note: See TracTickets for help on using tickets.