Re: [PATCH] x86/platform/uv/BAU: gracefully disable BAU during panic

From: Greg KH
Date: Sun Jun 03 2018 - 15:56:11 EST


On Sun, Jun 03, 2018 at 11:42:32AM -0500, Andrew Banman wrote:
> When panic happens while BAU is active there is a chance that
> outstanding broadcasts tie up BAU resources enough to cause timeouts in
> the UV ASIC. These timeouts are hardware errors that immediately bring
> down the system, preventing kdump from completing.
>
> Add uv_bau_crash_shutdown() to bring BAU to quiescence during panic before
> continuing with the native crash shutdown. Assign uv_bau_crash_shutdown
> to machine_ops during init.
>
> Signed-off-by: Andrew Banman <abanman@xxxxxxx>
> ---
> arch/x86/platform/uv/tlb_uv.c | 31 +++++++++++++++++++++++++++++++
> 1 file changed, 31 insertions(+)

<formletter>

This is not the correct way to submit patches for inclusion in the
stable kernel tree. Please read:
https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html
for how to do this properly.

</formletter>