From: Krzysztof Kozlowski <krzk@kernel.org>
To: Pavel Machek <pavel@ucw.cz>
Cc: "Andrew F. Davis" <afd@ti.com>, Pali Roh??r <pali@kernel.org>,
Sebastian Reichel <sre@kernel.org>,
Krzysztof Kozlowski <krzysztof.kozlowski@proceq.com>,
linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org
Subject: Re: [PATCH 1/2] power: supply: bq27xxx_battery: Notify about all battery changes
Date: Tue, 16 Jun 2020 13:57:41 +0200 [thread overview]
Message-ID: <20200616115741.GA13274@kozik-lap> (raw)
In-Reply-To: <20200616105224.GF1718@bug>
On Tue, Jun 16, 2020 at 12:52:24PM +0200, Pavel Machek wrote:
> 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.
It won't be 5 seconds but poll_interval which is 360 seconds by default.
It can be 5 seconds if user-space changes this time or if user-space
keeps asking for get_property. In first case: user-space kind of decided
about it... In second: user-space is already woken-up since it polls get
properties.
However I understand that this is quite intrusive change and maybe in
such case user-space should just keep polling (if it wants all data to
be provided every n-seconds).
Best regards,
Krzysztof
prev parent reply other threads:[~2020-06-16 11:57 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-25 14:11 [PATCH 1/2] power: supply: bq27xxx_battery: Notify about all battery changes Krzysztof Kozlowski
2020-05-25 14:12 ` [PATCH 2/2] power: supply: bq27xxx_battery: Notify about voltage and current changes Krzysztof Kozlowski
2020-05-27 1:24 ` [PATCH 1/2] power: supply: bq27xxx_battery: Notify about all battery changes Andrew F. Davis
2020-05-27 7:22 ` Krzysztof Kozlowski
2020-05-27 7:30 ` Krzysztof Kozlowski
2020-06-16 10:52 ` Pavel Machek
2020-06-16 11:57 ` Krzysztof Kozlowski [this message]
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