All of lore.kernel.org
 help / color / mirror / Atom feed
From: Tony Lindgren <tony@atomide.com>
To: Pavel Machek <pavel@ucw.cz>
Cc: kernel list <linux-kernel@vger.kernel.org>,
	linux-arm-kernel <linux-arm-kernel@lists.infradead.org>,
	linux-omap@vger.kernel.org, sre@kernel.org, nekit1000@gmail.com,
	mpartap@gmx.net, merlijn@wizzup.org
Subject: Re: Motorola Droid 4 progress, power consumption
Date: Thu, 3 May 2018 07:22:40 -0700	[thread overview]
Message-ID: <20180503142240.GQ98604@atomide.com> (raw)
In-Reply-To: <20180503090611.GA14451@amd>

* Pavel Machek <pavel@ucw.cz> [180503 09:08]:
> I'd like current_avg more, but if I cat it manually, it changes on
> order of seconds, and quite significantly... which suggest shorter
> polling interval would be needed.
> 
> user@devuan:/sys/class/power_supply/battery$ date; cat current_now
> current_avg
> Thu May  3 09:33:05 CEST 2018
> -71000
> -218408
> user@devuan:/sys/class/power_supply/battery$ date; cat current_now
> current_avg
> Thu May  3 09:33:06 CEST 2018
> -61000
> -200238
> user@devuan:/sys/class/power_supply/battery$ date; cat current_now
> current_avg
> Thu May  3 09:33:06 CEST 2018
> -51000
> -209879
> user@devuan:/sys/class/power_supply/battery$ date; cat current_now
> current_avg
> Thu May  3 09:33:07 CEST 2018
> -56000
> -72308
> user@devuan:/sys/class/power_supply/battery$ date; cat current_now
> current_avg
> Thu May  3 09:33:08 CEST 2018
> -37000
> -211362

I recall it just being calculated based on the time between
the reads. Hard to say what it does, -ENODOCS.. Maybe the mc13783
PMIC docs have something similar.

> > Hmm oh and the POWER_SUPPLY_CHARGE_COUNTER value should be monitored
> > by your libbattery and it's low value and high value should be saved
> > to a file. Low should be saved when we get the battery low interrupt
> > and battery state changes to POWER_SUPPLY_CAPACITY_LEVEL_CRITICAL.
> > High value should be saved on POWER_SUPPLY_CAPACITY_LEVEL_FULL.
> > 
> > Then when you know the high value and low value, you can calculate
> > the remaining capacity based on the current value and
> > POWER_SUPPLY_POWER_AVG.
> 
> I'll look into that... but probably will do experiments with python,
> first.

Sure. The reason why I think we should not do it in the kernel in
addition to the earlier reasoning is that we don't have a place
to store the min and max values across reboot. I think there's
some flash on the battery over 1w bus, but it probably just
contains battery serial number or something and is not intended
for writing much to it. I guess the min and max values should be
really keyd based on this battery id in case the battery gets
changed.

Regards,

Tony

WARNING: multiple messages have this Message-ID (diff)
From: tony@atomide.com (Tony Lindgren)
To: linux-arm-kernel@lists.infradead.org
Subject: Motorola Droid 4 progress, power consumption
Date: Thu, 3 May 2018 07:22:40 -0700	[thread overview]
Message-ID: <20180503142240.GQ98604@atomide.com> (raw)
In-Reply-To: <20180503090611.GA14451@amd>

* Pavel Machek <pavel@ucw.cz> [180503 09:08]:
> I'd like current_avg more, but if I cat it manually, it changes on
> order of seconds, and quite significantly... which suggest shorter
> polling interval would be needed.
> 
> user at devuan:/sys/class/power_supply/battery$ date; cat current_now
> current_avg
> Thu May  3 09:33:05 CEST 2018
> -71000
> -218408
> user at devuan:/sys/class/power_supply/battery$ date; cat current_now
> current_avg
> Thu May  3 09:33:06 CEST 2018
> -61000
> -200238
> user at devuan:/sys/class/power_supply/battery$ date; cat current_now
> current_avg
> Thu May  3 09:33:06 CEST 2018
> -51000
> -209879
> user at devuan:/sys/class/power_supply/battery$ date; cat current_now
> current_avg
> Thu May  3 09:33:07 CEST 2018
> -56000
> -72308
> user at devuan:/sys/class/power_supply/battery$ date; cat current_now
> current_avg
> Thu May  3 09:33:08 CEST 2018
> -37000
> -211362

I recall it just being calculated based on the time between
the reads. Hard to say what it does, -ENODOCS.. Maybe the mc13783
PMIC docs have something similar.

> > Hmm oh and the POWER_SUPPLY_CHARGE_COUNTER value should be monitored
> > by your libbattery and it's low value and high value should be saved
> > to a file. Low should be saved when we get the battery low interrupt
> > and battery state changes to POWER_SUPPLY_CAPACITY_LEVEL_CRITICAL.
> > High value should be saved on POWER_SUPPLY_CAPACITY_LEVEL_FULL.
> > 
> > Then when you know the high value and low value, you can calculate
> > the remaining capacity based on the current value and
> > POWER_SUPPLY_POWER_AVG.
> 
> I'll look into that... but probably will do experiments with python,
> first.

Sure. The reason why I think we should not do it in the kernel in
addition to the earlier reasoning is that we don't have a place
to store the min and max values across reboot. I think there's
some flash on the battery over 1w bus, but it probably just
contains battery serial number or something and is not intended
for writing much to it. I guess the min and max values should be
really keyd based on this battery id in case the battery gets
changed.

Regards,

Tony

  reply	other threads:[~2018-05-03 14:22 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-05-01 18:31 Motorola Droid 4 progress, power consumption Pavel Machek
2018-05-02 14:41 ` Tony Lindgren
2018-05-02 14:41   ` Tony Lindgren
2018-05-02 19:10   ` Pavel Machek
2018-05-02 19:10     ` Pavel Machek
2018-05-02 19:42     ` Tony Lindgren
2018-05-02 19:42       ` Tony Lindgren
2018-05-02 21:32       ` Pavel Machek
2018-05-02 21:32         ` Pavel Machek
2018-05-03  9:06   ` Pavel Machek
2018-05-03  9:06     ` Pavel Machek
2018-05-03 14:22     ` Tony Lindgren [this message]
2018-05-03 14:22       ` Tony Lindgren
2018-05-04 20:20       ` Pavel Machek
2018-05-04 20:20         ` Pavel Machek
2018-05-04 20:38         ` Tony Lindgren
2018-05-04 20:38           ` Tony Lindgren
2018-05-04 21:47           ` Pavel Machek
2018-05-04 21:47             ` Pavel Machek
2018-05-05 19:44             ` Tony Lindgren
2018-05-05 19:44               ` Tony Lindgren

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20180503142240.GQ98604@atomide.com \
    --to=tony@atomide.com \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-omap@vger.kernel.org \
    --cc=merlijn@wizzup.org \
    --cc=mpartap@gmx.net \
    --cc=nekit1000@gmail.com \
    --cc=pavel@ucw.cz \
    --cc=sre@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.