[Skiboot] [PATCH skiboot] npu2: Clear fence state for a brick being reset

[Stewart Smith]

Alexey Kardashevskiy <aik at ozlabs.ru> writes:
> Resetting a GPU before resetting an NVLink leads to occasional HMIs
> which fence some bricks and prevent the "reset_ntl" procedure from
> succeeding at the "reset_ntl_release" step - the host system requires
> reboot; there may be other cases like this as well.
>
> This adds clearing of the fence bit in NPU.MISC.FENCE_STATE for
> the NVLink which we are about to reset.
>
> Signed-off-by: Alexey Kardashevskiy <aik at ozlabs.ru>
> ---
>
> This one recovers from HMIs reported in
> https://bugzilla.linux.ibm.com/show_bug.cgi?id=176564
>
> but HMIs are still printed (and scare users) and
> "npu2: Reset NVLinks when resetting a GPU" prevents those particular
> HMIs from happening at all (does not scare users).
> ---
>  hw/npu2-hw-procedures.c | 8 ++++++++
>  1 file changed, 8 insertions(+)

Merged to master as of d496bb141c978a6dc8a106b3d92e5fc1ad0f8663
-- 
Stewart Smith
OPAL Architect, IBM.