linux-kernel - Re: [PATCH 2/5] powernv:idle: Change return type of pnv_probe_idle

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Date:   Fri, 7 Jul 2017 17:56:38 +0530
From:   Gautham R Shenoy <ego@...ux.vnet.ibm.com>
To:     Nicholas Piggin <npiggin@...il.com>
Cc:     "Gautham R. Shenoy" <ego@...ux.vnet.ibm.com>,
        Michael Ellerman <mpe@...erman.id.au>,
        Michael Neuling <mikey@...ling.org>,
        Vaidyanathan Srinivasan <svaidy@...ux.vnet.ibm.com>,
        Shilpasri G Bhat <shilpa.bhat@...ux.vnet.ibm.com>,
        "Rafael J. Wysocki" <rafael@...nel.org>,
        Akshay Adiga <akshay.adiga@...ux.vnet.ibm.com>,
        linuxppc-dev@...ts.ozlabs.org, linux-kernel@...r.kernel.org,
        linux-pm@...r.kernel.org
Subject: Re: [PATCH 2/5] powernv:idle: Change return type of
 pnv_probe_idle_states to int

Hello Nicholas,

On Fri, Jul 07, 2017 at 01:01:49AM +1000, Nicholas Piggin wrote:
> On Wed,  5 Jul 2017 22:08:13 +0530
> "Gautham R. Shenoy" <ego@...ux.vnet.ibm.com> wrote:
> 
> > From: "Gautham R. Shenoy" <ego@...ux.vnet.ibm.com>
> > 
> > In the current idle initialization code, if there are failures in
> > pnv_probe_idle_states, then no platform idle state is
> > enabled. However, since the error is not propagated to the top-level
> > function pnv_init_idle_states, we continue initialization in this
> > top-level function even though this will never be used.
> > 
> > Hence change the the return type of pnv_probe_idle_states from void to
> > int and in case of failures, bail out early on in
> > pnv_init_idle_states.
> > 
> > Signed-off-by: Gautham R. Shenoy <ego@...ux.vnet.ibm.com>
> 
> Looks good to me.
> 
> Reviewed-by: Nicholas Piggin <npiggin@...il.com>
> 
> I wonder if the warnings are strong enough here to let people know
> idle won't be used so power consumption will be high and performance
> significantly reduced on SMT machines?

Good point. Will try to print an error message to this effect.

--
Thanks and Regards
gautham.