[patch 10/12] acpi: preserve correct battery state through suspend/resume cycles

[patch 10/12] acpi: preserve correct battery state through suspend/resume cycles

[akpm]

From: Jiri Kosina <jikos@jikos.cz>

There is a problem in th following scenario(s):

boot -> suspend -> (un)plug battery -> resume

The problem arises in both cases - i.e.  suspend with battery plugged in,
and resume with battery unplugged, or vice versa.

After resume, when the battery status has changed (plugged in -> unplegged
or unplugged -> plugged in) during the time when the system was sleeping,
the /proc/acpi/battery/*/* is wrong (showing the state before suspend, not
the current state).

The following patch adds ->resume method to the ACPI battery handler, which
has the only aim - to check whether the battery state has changed during
sleep, and if so, update the ACPI internal data structures, so that
information published through /proc/acpi/battery/*/* is correct even after
suspend/resume cycle, during which the battery was removed/inserted.

The patch is against current ACPI git tree, but applies cleanly also
against -mm and probably other trees. Please apply.

Signed-off-by: Jiri Kosina <jikos@jikos.cz>
Cc: "Brown, Len" <len.brown@intel.com>
Cc: Stefan Seyfried <seife@suse.de>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---

 drivers/acpi/battery.c |   14 ++++++++++++++
 1 files changed, 14 insertions(+)

diff -puN drivers/acpi/battery.c~acpi-preserve-correct-battery-state-through-suspend-resume-cycles drivers/acpi/battery.c
--- a/drivers/acpi/battery.c~acpi-preserve-correct-battery-state-through-suspend-resume-cycles
+++ a/drivers/acpi/battery.c
@@ -64,6 +64,7 @@ extern void *acpi_unlock_battery_dir(str
 
 static int acpi_battery_add(struct acpi_device *device);
 static int acpi_battery_remove(struct acpi_device *device, int type);
+static int acpi_battery_resume(struct acpi_device *device, int status);
 
 static struct acpi_driver acpi_battery_driver = {
 	.name = ACPI_BATTERY_DRIVER_NAME,
@@ -71,6 +72,7 @@ static struct acpi_driver acpi_battery_d
 	.ids = ACPI_BATTERY_HID,
 	.ops = {
 		.add = acpi_battery_add,
+		.resume = acpi_battery_resume,
 		.remove = acpi_battery_remove,
 		},
 };
@@ -753,6 +755,18 @@ static int acpi_battery_remove(struct ac
 	return 0;
 }
 
+/* this is needed to learn about changes made in suspended state */
+static int acpi_battery_resume(struct acpi_device *device, int state)
+{
+	struct acpi_battery *battery;
+
+	if (!device)
+		return -EINVAL;
+
+	battery = device->driver_data;
+	return acpi_battery_check(battery);
+}
+
 static int __init acpi_battery_init(void)
 {
 	int result;
_

Re: [patch 10/12] acpi: preserve correct battery state through suspend/resume cycles

[Richard Hughes]

On Tue, 2006-10-10 at 14:20 -0700, akpm@osdl.org wrote:
> 
> The following patch adds ->resume method to the ACPI battery handler,
> which
> has the only aim - to check whether the battery state has changed
> during
> sleep, and if so, update the ACPI internal data structures, so that
> information published through /proc/acpi/battery/*/* is correct even
> after
> suspend/resume cycle, during which the battery was removed/inserted.

This would be great for gnome-power-manager and HAL. I've got open
bugzillas about this.

Richard.

Re: [patch 10/12] acpi: preserve correct battery state through suspend/resume cycles

[Len Brown]

Applied.

thanks,
-Len

On Tuesday 10 October 2006 17:20, akpm@osdl.org wrote:
> From: Jiri Kosina <jikos@jikos.cz>
> 
> There is a problem in th following scenario(s):
> 
> boot -> suspend -> (un)plug battery -> resume
> 
> The problem arises in both cases - i.e.  suspend with battery plugged in,
> and resume with battery unplugged, or vice versa.
> 
> After resume, when the battery status has changed (plugged in -> unplegged
> or unplugged -> plugged in) during the time when the system was sleeping,
> the /proc/acpi/battery/*/* is wrong (showing the state before suspend, not
> the current state).
> 
> The following patch adds ->resume method to the ACPI battery handler, which
> has the only aim - to check whether the battery state has changed during
> sleep, and if so, update the ACPI internal data structures, so that
> information published through /proc/acpi/battery/*/* is correct even after
> suspend/resume cycle, during which the battery was removed/inserted.
> 
> The patch is against current ACPI git tree, but applies cleanly also
> against -mm and probably other trees. Please apply.
> 
> Signed-off-by: Jiri Kosina <jikos@jikos.cz>
> Cc: "Brown, Len" <len.brown@intel.com>
> Cc: Stefan Seyfried <seife@suse.de>
> Acked-by: Pavel Machek <pavel@ucw.cz>
> Signed-off-by: Andrew Morton <akpm@osdl.org>
> ---
> 
>  drivers/acpi/battery.c |   14 ++++++++++++++
>  1 files changed, 14 insertions(+)
> 
> diff -puN drivers/acpi/battery.c~acpi-preserve-correct-battery-state-through-suspend-resume-cycles drivers/acpi/battery.c
> --- a/drivers/acpi/battery.c~acpi-preserve-correct-battery-state-through-suspend-resume-cycles
> +++ a/drivers/acpi/battery.c
> @@ -64,6 +64,7 @@ extern void *acpi_unlock_battery_dir(str
>  
>  static int acpi_battery_add(struct acpi_device *device);
>  static int acpi_battery_remove(struct acpi_device *device, int type);
> +static int acpi_battery_resume(struct acpi_device *device, int status);
>  
>  static struct acpi_driver acpi_battery_driver = {
>  	.name = ACPI_BATTERY_DRIVER_NAME,
> @@ -71,6 +72,7 @@ static struct acpi_driver acpi_battery_d
>  	.ids = ACPI_BATTERY_HID,
>  	.ops = {
>  		.add = acpi_battery_add,
> +		.resume = acpi_battery_resume,
>  		.remove = acpi_battery_remove,
>  		},
>  };
> @@ -753,6 +755,18 @@ static int acpi_battery_remove(struct ac
>  	return 0;
>  }
>  
> +/* this is needed to learn about changes made in suspended state */
> +static int acpi_battery_resume(struct acpi_device *device, int state)
> +{
> +	struct acpi_battery *battery;
> +
> +	if (!device)
> +		return -EINVAL;
> +
> +	battery = device->driver_data;
> +	return acpi_battery_check(battery);
> +}
> +
>  static int __init acpi_battery_init(void)
>  {
>  	int result;
> _
> -
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