From: Andrey Borzenkov <arvidjaar@mail.ru>
To: cbou@mail.ru
Cc: linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org,
dwmw2@infradead.org, Alexey Starikovskiy <aystarik@gmail.com>
Subject: Re: [PATCH] 2.6.24-rc1: ensure "present" sysfs attribute even if battery is absent
Date: Sun, 28 Oct 2007 10:50:45 +0400 [thread overview]
Message-ID: <200710280950.46779.arvidjaar@mail.ru> (raw)
In-Reply-To: <20071027184249.GA2982@zarina>
[-- Attachment #1: Type: text/plain, Size: 1632 bytes --]
On Saturday 27 October 2007, Anton Vorontsov wrote:
> On Sat, Oct 27, 2007 at 08:54:30PM +0400, Andrey Borzenkov wrote:
> > I am not exactly sure about this one ... what other power_supply class
> > drivers do? Should I fix HAL instead (but then, I do not know whether HAL
> > is the only application that is using this interface).
>
> Well, PROP_PRESENT wasn't my idea, currently it's used by pmu and
> olpc drivers becuase it's not trivial to register/unregister their
> batteries on physical insertion/removal. I have some plans to teach
> at least pmu batteries to not use PROP_PRESENT. I don't have any
> OLPC, thus I can't convert it.
>
> To sum this: the good way to handle "missing" batteries is to
> unregister them, so they'll not show up in the /sys/class/power_supply.
Well, in this case HAL behaviour makes sense (default to present == true
if "present" attribute is missing)
> Is that possible with the ACPI?
>
At least looking in ACPI specs, this looks possible. What currently is
presented as battery object is actually battery bay according to ACPI spec:
Unlike most other devices, when a battery is inserted or removed from the
system, the device itself (the
battery bay) is still considered to be present in the system.
When battery is inserted/removed, ACPI notifies us and we can check whether
battery is actually present and update registration accordingly. From the
sysfs structure POV probably nothing has to be changed; just when and how
power_supply is registered
under /sys/devices/LNXSYSTM:00/device:00/PNP0C0A:0n
Alexey, does it make sense (or doable)?
[-- Attachment #2: This is a digitally signed message part. --]
[-- Type: application/pgp-signature, Size: 189 bytes --]
next prev parent reply other threads:[~2007-10-28 6:51 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-10-27 16:54 [PATCH] 2.6.24-rc1: ensure "present" sysfs attribute even if battery is absent Andrey Borzenkov
2007-10-27 17:16 ` Alexey Starikovskiy
2007-10-27 17:50 ` Andrey Borzenkov
2007-10-27 18:18 ` Alexey Starikovskiy
2007-10-27 18:42 ` Anton Vorontsov
2007-10-27 19:32 ` David Woodhouse
2007-10-27 19:50 ` Anton Vorontsov
2007-10-28 6:50 ` Andrey Borzenkov [this message]
2007-10-28 7:37 ` [PATCH] [2.6.24-rc] ACPI: register power_supply subdevice only when battery is present Andrey Borzenkov
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=200710280950.46779.arvidjaar@mail.ru \
--to=arvidjaar@mail.ru \
--cc=aystarik@gmail.com \
--cc=cbou@mail.ru \
--cc=dwmw2@infradead.org \
--cc=linux-acpi@vger.kernel.org \
--cc=linux-kernel@vger.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