ACK: [PATCH][Zesty] SAUCE: powerpc: Fix /proc/cpuinfo revision for POWER9 DD2

Seth Forshee seth.forshee at canonical.com
Tue Jun 20 13:12:32 UTC 2017


On Mon, Jun 19, 2017 at 11:58:52AM -0300, Breno Leitao wrote:
> From: Michael Neuling <mikey at neuling.org>
> 
> BugLink: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1698844
> 
> The P9 PVR bits 12-15 don't indicate a revision but instead different
> chip configurations.  From BookIV we have:
>    Bits      Configuration
>     0 :    Scale out 12 cores
>     1 :    Scale out 24 cores
>     2 :    Scale up  12 cores
>     3 :    Scale up  24 cores
> 
> DD1 doesn't use this but DD2 does. Linux will mostly use the "Scale
> out 24 core" configuration (ie. SMT4 not SMT8) which results in a PVR
> of 0x004e1200. The reported revision in /proc/cpuinfo is hence
> reported incorrectly as "18.0".
> 
> This patch fixes this to mask off only the relevant bits for the major
> revision (ie. bits 8-11) for POWER9.
> 
> Signed-off-by: Michael Neuling <mikey at neuling.org>
> Signed-off-by: Breno Leitao <leitao at debian.org>

One small nit, the subject should start with "UBUNTU: SAUCE:" for sauce
patches and not just "SAUCE:". But that can be fixed when applied.

Acked-by: Seth Forshee <seth.forshee at canonical.com>

Also applied to artful/master-next.




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