Ticket #1770 (assigned defect)

Opened 11 years ago

Last modified 10 years ago

NAND u-boot jams FM radio

Reported by: h.koenig Owned by: hardware
Priority: normal Milestone:
Component: hardware Version:
Severity: normal Keywords:
Cc: Blocked By:
Blocking: Estimated Completion (week):
HasPatchForReview: no PatchReviewResult:
Reproducible:

Description

I just booted my FR using the NAND uboot and heart loud interferences in my FM radio which is at a distance of 1.5-2 meter.

looks like I should have the FM radio running more often to check for EMV problems ;-)

Change History

comment:1 Changed 10 years ago by john_lee

  • Status changed from new to assigned
  • Owner changed from openmoko-devel to hardware
  • HasPatchForReview unset
  • Component changed from unknown to hardware

err, exactly what should we do about this?

comment:2 Changed 10 years ago by werner

Hmm, maybe ask our hw folks to hold an antenna up in the air and look
with a spectrum analyzer what this is. Seems pretty strong.

comment:3 Changed 10 years ago by andy

Our memory clock is 100MHz on GTA02, that is in FM band. It also comes out of CPU to external SDRAM chip.

On GTA03 all the SDRAM is in the CPU and the actual base clock is 133MHz.

If this thing only happens in U-Boot and not kernel for whatever reason, we will change to Qi soon which spends only a couple of seconds in the bootloader anyway, so I guess that is the fix.

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