linux-kernel - Re: [PATCH 1/2] power: supply: bq27xxx_battery: Notify about all battery changes

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Message-ID: <20200616105224.GF1718@bug>
Date:   Tue, 16 Jun 2020 12:52:24 +0200
From:   Pavel Machek <pavel@....cz>
To:     "Andrew F. Davis" <afd@...com>
Cc:     Krzysztof Kozlowski <krzk@...nel.org>,
        Pali Roh??r <pali@...nel.org>,
        Sebastian Reichel <sre@...nel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski@...ceq.com>,
        linux-kernel@...r.kernel.org, linux-pm@...r.kernel.org
Subject: Re: [PATCH 1/2] power: supply: bq27xxx_battery: Notify about all
 battery changes

On Tue 2020-05-26 21:24:39, Andrew F. Davis wrote:
> On 5/25/20 10:11 AM, Krzysztof Kozlowski wrote:
> > All battery related data could be important for user-space.  For example
> > time-to-full could be shown to user on the screen or health could be
> > monitored for any issues.  Instead of comparing few selected old/new
> > values, just check if anything changed in the cache.
> > 
> 
> 
> At least some value will change every time we poll the battery, are we
> okay with having power_supply_changed() called every time?

I believe that's very bad idea. AFAICT that would wake up userspace every
5 seconds, eating power in unexpected way, and without easy ability of opting
out. IOW a regression.

									Pavel
-- 
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