Re: 2.6.24-rc1: OOPS at acpi_battery_update

[Johannes Weiner <hannes@saeurebad.de>]

Hi,

On Thu, Nov 08, 2007 at 07:11:53PM +0300, Alexey Starikovskiy wrote:
> Rafael J. Wysocki wrote:
> >On Thursday, 8 of November 2007, Johannes Weiner wrote:
> >>Hi,
> >>
> >>is there any reason, why acpi_battery_get_property() should call
> >>acpi_battery_update() at all?
> >
> >Alex?
> If someone wants to read stale values, he could comment out 
> acpi_battery_update.

Please help me to understand:

When the battery is plugged in, the acpi_battery_notify() is called,
which in turn calls acpi_battery_update(). The latter ensures that the
sysfs files are created if not yet present.

When the battery is removed, acpi_battery_notify is called, which in
turn calls acpi_battery_update(). The latter ensures that the sysfs
files are removed if present.

During runtime - as far as I understood - no sysfs files have to be
created/removed but the saved battery state info becomes stale.

So, would it be enough to call acpi_battery_get_state() in
acpi_battery_get_property() instead of acpi_battery_update()?

If acpi_battery_get_state() does what I think it does, this would
ensure that the battery state is reread and updated when
acpi_battery_get_property() is called.

Hit me.

	Hannes