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Date:   Mon, 13 Jul 2020 15:23:21 +1000
From:   Nicholas Piggin <npiggin@gmail.com>
Subject: Re: [PATCH v2 0/3] Power10 basic energy management
To:     benh@kernel.crashing.org, ego@linux.vnet.ibm.com,
        linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
        mikey@neuling.org, mpe@ellerman.id.au, paulus@samba.org,
        pratik.r.sampat@gmail.com,
        Pratik Rajesh Sampat <psampat@linux.ibm.com>,
        ravi.bangoria@linux.ibm.com, svaidy@linux.ibm.com
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Excerpts from Pratik Rajesh Sampat's message of July 10, 2020 3:22 pm:
> Changelog v1 --> v2:
> 1. Save-restore DAWR and DAWRX unconditionally as they are lost in
> shallow idle states too
> 2. Rename pnv_first_spr_loss_level to pnv_first_fullstate_loss_level to
> correct naming terminology
>=20
> Pratik Rajesh Sampat (3):
>   powerpc/powernv/idle: Exclude mfspr on HID1,4,5 on P9 and above
>   powerpc/powernv/idle: save-restore DAWR0,DAWRX0 for P10
>   powerpc/powernv/idle: Rename pnv_first_spr_loss_level variable
>=20
>  arch/powerpc/platforms/powernv/idle.c | 34 +++++++++++++++++----------
>  1 file changed, 22 insertions(+), 12 deletions(-)

These look okay to me, but the CPU_FTR_ARCH_300 test for=20
pnv_power9_idle_init() is actually wrong, it should be a PVR test=20
because idle is not completely architected (not even shallow stop=20
states, unfortunately).

It doesn't look like we support POWER10 idle correctly yet, and on older
kernels it wouldn't work even if we fixed newer, so ideally the PVR=20
check would be backported as a fix in the front of the series.

Sadly, we have no OPAL idle driver yet. Hopefully we will before the
next processor shows up :P

Thanks,
Nick