linux-kernel - Re: [PATCH 3/6] hwrng: omap3-rom - Call clk

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Message-ID: <20190914175759.GV52127@atomide.com>
Date:   Sat, 14 Sep 2019 10:57:59 -0700
From:   Tony Lindgren <tony@...mide.com>
To:     Sebastian Reichel <sre@...nel.org>
Cc:     Matt Mackall <mpm@...enic.com>,
        Herbert Xu <herbert@...dor.apana.org.au>,
        linux-kernel@...r.kernel.org, linux-omap@...r.kernel.org,
        linux-crypto@...r.kernel.org, Aaro Koskinen <aaro.koskinen@....fi>,
        Adam Ford <aford173@...il.com>,
        Pali Rohár <pali.rohar@...il.com>,
        Tero Kristo <t-kristo@...com>,
        Rob Herring <robh+dt@...nel.org>, devicetree@...r.kernel.org
Subject: Re: [PATCH 3/6] hwrng: omap3-rom - Call clk_prepare() on init and
 exit only

* Sebastian Reichel <sre@...nel.org> [190914 13:01]:
> Hi,
> 
> On Fri, Sep 13, 2019 at 03:09:19PM -0700, Tony Lindgren wrote:
> > Also, we should not call prepare and unprepare except during init, and
> > only call enable and disable during use.
> 
> Why? Usually clk_(un)prepare() is the part saving most power, so I
> would expect the runtime resume handlers to call clk_prepare_enable
> and vice versa in the suspend handler.

Sure yeah fine with me, clk_prepare_enable() is more generic at the
cost of some extra calls to toggle a clock gate bit :) Let's also
forget the probe changes, those will get cleared with the runtime
PM changes anyways.

Regards,

Tony