USB Host port inoperative after kexec on Beagleboard

Peter Chubb peter.chubb at
Mon Jan 9 17:02:19 EST 2012

Hi Will,
   Thanks for the fixes to kexec for ARM that went into mainline this
   week.  Mostly things work now.

   One issue: the USB EHCI port on the (rev C2) beagleboard doesn't
   work after a kexec.  During boot after kexec, the host device is
   detected and initialised, but nothing plugged in works, even when
   everything was working corectly before the kexec.  Das U-boot
   must set up something that is then undone during the kexec reboot.

   I've traced all calls to clk_enable() and clk_disable(), and
   everything looks all right --- in particular I can't see 
   anything explicitly disabled during kexec that isn't reenabled
   during boot of the subsequent kernel.

   Voltages that I can measure look correct on the port.

   Do you have any suggestions as to what else could be wrong?
Dr Peter Chubb  peterc AT           ERTOS within National ICT Australia

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