[Acked] [Trusty SRU] ACPI / battery: Accelerate battery resume callback

[Andy Whitcroft]

On Thu, Nov 06, 2014 at 03:15:34PM +0800, AceLan Kao wrote:
> From: Lan Tianyu <tianyu.lan at intel.com>
> 
> BugLink: https://bugs.launchpad.net/bugs/838543
> 
> Most time of battery resume callback is spent on executing AML code
> _BTP, _BIF and _BIF to get battery info, status and set alarm. These
> AML methods may access EC operation regions several times and consumes
> time.
> 
> These operations are not necessary during devices resume and can run
> during POST_SUSPEND/HIBERNATION event when all processes are thawed.
> 
> This also can avoid removing and adding battery sysfs nodes every system
> resume even if the battery unit is not actually changed. The original code
> updates sysfs nodes without check and this seems not reasonable.
> 
> Signed-off-by: Lan Tianyu <tianyu.lan at intel.com>
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki at intel.com>
> (backported from commit 9e50bc14a7f58b5d8a55973b2d69355852ae2dae)
> Signed-off-by: AceLan Kao <acelan.kao at canonical.com>
> 
> Conflicts:
> 	drivers/acpi/battery.c
> ---
>  drivers/acpi/battery.c | 36 +++++++++++++++++++++++++++---------
>  1 file changed, 27 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/acpi/battery.c b/drivers/acpi/battery.c
> index 2928e95..fabd751 100644
> --- a/drivers/acpi/battery.c
> +++ b/drivers/acpi/battery.c
> @@ -700,7 +700,7 @@ static void acpi_battery_quirks(struct acpi_battery *battery)
>  	}
>  }
>  
> -static int acpi_battery_update(struct acpi_battery *battery)
> +static int acpi_battery_update(struct acpi_battery *battery, bool resume)
>  {
>  	int result, old_present = acpi_battery_present(battery);
>  	result = acpi_battery_get_status(battery);
> @@ -711,6 +711,10 @@ static int acpi_battery_update(struct acpi_battery *battery)
>  		battery->update_time = 0;
>  		return 0;
>  	}
> +
> +	if (resume)
> +		return 0;
> +
>  	if (!battery->update_time ||
>  	    old_present != acpi_battery_present(battery)) {
>  		result = acpi_battery_get_info(battery);
> @@ -919,7 +923,7 @@ static print_func acpi_print_funcs[ACPI_BATTERY_NUMFILES] = {
>  static int acpi_battery_read(int fid, struct seq_file *seq)
>  {
>  	struct acpi_battery *battery = seq->private;
> -	int result = acpi_battery_update(battery);
> +	int result = acpi_battery_update(battery, false);
>  	return acpi_print_funcs[fid](seq, result);
>  }
>  
> @@ -1034,7 +1038,7 @@ static void acpi_battery_notify(struct acpi_device *device, u32 event)
>  	old = battery->bat.dev;
>  	if (event == ACPI_BATTERY_NOTIFY_INFO)
>  		acpi_battery_refresh(battery);
> -	acpi_battery_update(battery);
> +	acpi_battery_update(battery, false);
>  	acpi_bus_generate_netlink_event(device->pnp.device_class,
>  					dev_name(&device->dev), event,
>  					acpi_battery_present(battery));
> @@ -1048,13 +1052,27 @@ static int battery_notify(struct notifier_block *nb,
>  {
>  	struct acpi_battery *battery = container_of(nb, struct acpi_battery,
>  						    pm_nb);
> +	int result;
> +
>  	switch (mode) {
>  	case PM_POST_HIBERNATION:
>  	case PM_POST_SUSPEND:
> -		if (battery->bat.dev) {
> -			sysfs_remove_battery(battery);
> -			sysfs_add_battery(battery);
> -		}
> +		if (!acpi_battery_present(battery))
> +			return 0;
> +
> +		if (!battery->bat.dev) {
> +			result = acpi_battery_get_info(battery);
> +			if (result)
> +				return result;
> +
> +			result = sysfs_add_battery(battery);
> +			if (result)
> +				return result;
> +		} else
> +			acpi_battery_refresh(battery);
> +
> +		acpi_battery_init_alarm(battery);
> +		acpi_battery_get_state(battery);
>  		break;
>  	}
>  
> @@ -1085,7 +1103,7 @@ static int acpi_battery_update_retry(struct acpi_battery *battery)
>  	int retry, ret;
>  
>  	for (retry = 5; retry; retry--) {
> -		ret = acpi_battery_update(battery);
> +		ret = acpi_battery_update(battery, false);
>  		if (!ret)
>  			break;
>  
> @@ -1176,7 +1194,7 @@ static int acpi_battery_resume(struct device *dev)
>  		return -EINVAL;
>  
>  	battery->update_time = 0;
> -	acpi_battery_update(battery);
> +	acpi_battery_update(battery, true);
>  	return 0;
>  }
>  #endif

Looks reasonable.  Cirtainly ripping out and shoving back the battery
every time seems excessive.

Acked-by: Andy Whitcroft <apw at canonical.com>

As this is generic we do want to make sure this is tested on a variety
of other laptops.

-apw