[PATCH 0/3] Reduce probability U-Boot puts USB to Insane Spam Mode and kills function and 500mA host charging in Linux

Andy Green andy at openmoko.com
Fri Aug 1 08:54:07 CEST 2008

Mickey Lauer noticed that he wasn't able to enumerate to his host PC


Further investigation showed that with ~50% probability, current U-Boot
sets USB into "insane spam mode" that it does not recover from even in
Linux.  Due to the babble nature of the problem, host PC can't enumerate
the GTA02 at all, and that means we can't transition to 500mA charging
as well as not operate as a USB gadget.

These patches reduce time taken in time-critical code and move the
U-Boot recognition of enumeration action to the loop that waits for
power when battery is low.  It doesn't completely solve the problem yet,
but it reduces the probability of entering "insane spam mode" to
~10% from ~50%.


Andy Green (3):

 board/neo1973/common/udc.c     |   14 ++++++++++++--
 board/neo1973/gta02/gta02.c    |    6 ++++++
 common/cmd_bootm.c             |    7 +++++++
 drivers/serial/usbtty.c        |   16 ++++++++++++++--
 drivers/usb/usbdcore.c         |    6 ++++++
 drivers/usb/usbdcore_s3c2410.c |    9 ++++++---
 6 files changed, 51 insertions(+), 7 deletions(-)


More information about the openmoko-kernel mailing list