From: Hans de Goede <hdegoede@redhat.com>
To: "Thomas Koch" <linrunner@gmx.net>,
"Sebastian Reichel" <sre@kernel.org>,
"Barnabás Pőcze" <pobrn@protonmail.com>
Cc: Nicolo' Piazzalunga <nicolopiazzalunga@gmail.com>,
"platform-driver-x86@vger.kernel.org"
<platform-driver-x86@vger.kernel.org>,
Mark Pearson <markpearson@lenovo.com>,
Nitin Joshi1 <njoshi1@lenovo.com>,
"jwrdegoede@fedoraproject.org" <jwrdegoede@fedoraproject.org>,
"smclt30p@gmail.com" <smclt30p@gmail.com>
Subject: Re: [PATCH 1/3] thinkpad_acpi: add support for force_discharge
Date: Tue, 13 Apr 2021 10:05:12 +0200 [thread overview]
Message-ID: <6f58903f-5219-9aff-78ca-33687e2e4147@redhat.com> (raw)
In-Reply-To: <39c3436a-a08d-9530-3215-854148215312@gmx.net>
Hi,
On 4/9/21 8:33 PM, Thomas Koch wrote:
> Hi,
>
> On 08.04.21 15:51, Sebastian Reichel wrote:
>
>> IIUIC you have 'force_discharge', which basically means the system
>> is running from battery power despite an AC adapter being connected
>> and 'inhibit_discharge', which inhibits charging, so system does not
>> charge battery when AC is connected, but uses AC to supply itself
>> (so battery is idle)?
>>
>> We already have this kind of features on embedded systems (which
>> often provide all kind of charger details). Those drivers solve
>> this by having a writable 'status' property in the charger device:
>>
>> What: /sys/class/power_supply/<supply_name>/status
>> Date: May 2007
>> Contact: linux-pm@vger.kernel.org
>> Description:
>> Represents the charging status of the battery. Normally this
>> is read-only reporting although for some supplies this can be
>> used to enable/disable charging to the battery.
>>
>> Access: Read, Write
>>
>> Valid values:
>> "Unknown", "Charging", "Discharging",
>> "Not charging", "Full"
>>
>> If I do not miss anything writing "Discharging" is the same as forced
>> discharge and "Not Charging" (AKA Idle) is the same as your inhibit feature.
>
> There are ThinkPads with two batteries (BAT0, BAT1) and the hardware
> allows to select which one to discharge. An approach through
> /sys/class/power_supply/AC/status won't cover this.
The mentioned status strings come from /sys/class/power_supply/VAT#/status,
rather then from /sys/class/power_supply/AC/status.
There is one problem though, which is that the status attribute is being
managed by drivers/acpi/battery.c. There is infra for a driver like
the thinkpad_apci driver to add new attributes to a power_supply but
AFAIK there is no infra to say intercept writes to an attribute where
the reading is handled by another driver.
I guess we could add some special hook to allow another driver to
intercept status writes.
Sebastian, what is your take on this ?
Regards,
Hans
next prev parent reply other threads:[~2021-04-13 8:05 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-17 14:01 [PATCH 1/3] thinkpad_acpi: add support for force_discharge Nicolo' Piazzalunga
2021-04-07 10:24 ` Hans de Goede
2021-04-07 10:33 ` Barnabás Pőcze
2021-04-08 13:51 ` Sebastian Reichel
2021-04-08 18:18 ` Thomas Koch
2021-04-09 18:33 ` Thomas Koch
2021-04-13 8:05 ` Hans de Goede [this message]
2021-04-17 11:49 ` Thomas Koch
2021-04-17 17:03 ` Hans de Goede
2021-05-19 14:45 ` Nicolo' Piazzalunga
2021-04-07 12:19 ` Thomas Koch
2021-04-07 17:48 ` [External] " Mark Pearson
[not found] ` <VI1PR09MB2302B7C3AD8014CC98D36AA595759@VI1PR09MB2302.eurprd09.prod.outlook.com>
2021-04-12 17:10 ` Mark Pearson
2021-09-27 13:59 ` Mark Pearson
2021-09-27 15:00 ` Nicolò Piazzalunga
2021-09-27 15:12 ` Hans de Goede
2021-09-27 16:50 ` [External] " Mark Pearson
2021-09-29 5:47 ` Thomas Koch
2021-09-29 9:55 ` Hans de Goede
2021-09-29 10:45 ` Thomas Koch
2021-09-29 10:56 ` Hans de Goede
2021-09-29 13:45 ` [External] " Mark Pearson
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=6f58903f-5219-9aff-78ca-33687e2e4147@redhat.com \
--to=hdegoede@redhat.com \
--cc=jwrdegoede@fedoraproject.org \
--cc=linrunner@gmx.net \
--cc=markpearson@lenovo.com \
--cc=nicolopiazzalunga@gmail.com \
--cc=njoshi1@lenovo.com \
--cc=platform-driver-x86@vger.kernel.org \
--cc=pobrn@protonmail.com \
--cc=smclt30p@gmail.com \
--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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).