Missing USB XHCI and EHCI reset for kexec

From: Stefani Seibold
Date: Sun Apr 13 2014 - 15:23:44 EST


When executing a kexec kernel on a PowerPC board the new started kernel
will not find already enumerated USB devices due a missing reset on the
USB bus.

As a work around a

echo 1 >/sys/bus/pci/drivers/[ex]hci-pci/BUS-ADDRESS-OF-THE-HCD/reset

will solve this. But this is far from beauty.

My latest kernel without this issue was for EHCI kernel 2.6.39 and for
XHCI kernel 3.4, but i have no idea when exactly this behavior was
introduced.

For X86 all is fine.


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