On Tue, 2017-02-07 at 10:01:01 UTC, Michael Ellerman wrote:
> Currently the opal_exit tracepoint usually shows the opcode as 0:
>
> <idle>-0 [047] d.h. 635.654292: opal_entry: opcode=63
> <idle>-0 [047] d.h. 635.654296: opal_exit: opcode=0 retval=0
> kopald-1209 [019] d... 636.420943: opal_entry: opcode=10
> kopald-1209 [019] d... 636.420959: opal_exit: opcode=0 retval=0
>
> This is because we incorrectly load the opcode into r0 before calling
> __trace_opal_exit(), whereas it expects the opcode in r3 (first function
> parameter). In fact we are leaving the retval in r3, so opcode and
> retval will always show the same value.
>
> Instead load the opcode into r3, resulting in:
>
> <idle>-0 [040] d.h. 636.618625: opal_entry: opcode=63
> <idle>-0 [040] d.h. 636.618627: opal_exit: opcode=63 retval=0
>
> Fixes: c49f63530bb6 ("powernv: Add OPAL tracepoints")
> Signed-off-by: Michael Ellerman <m...@ellerman.id.au>
Applied to powerpc next.
https://git.kernel.org/powerpc/c/a7e0fb6c2029a780444d09560f739e
cheers
