From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-Id: <20120607040347.636736493@linuxfoundation.org> Date: Thu, 07 Jun 2012 13:04:52 +0900 From: Greg KH To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Andy Whitcroft , Ralf Jung , Len Brown Subject: [ 76/82] ACPI battery: only refresh the sysfs files when pertinent information changes In-Reply-To: <20120607041406.GA13233@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Andy Whitcroft commit c5971456964290da7e98222892797b71ef793e62 upstream. We only need to regenerate the sysfs files when the capacity units change, avoid the update otherwise. The origin of this issue is dates way back to 2.6.38: da8aeb92d4853f37e281f11fddf61f9c7d84c3cd (ACPI / Battery: Update information on info notification and resume) Signed-off-by: Andy Whitcroft Tested-by: Ralf Jung Signed-off-by: Len Brown Signed-off-by: Greg Kroah-Hartman --- drivers/acpi/battery.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) --- a/drivers/acpi/battery.c +++ b/drivers/acpi/battery.c @@ -643,11 +643,19 @@ static int acpi_battery_update(struct ac static void acpi_battery_refresh(struct acpi_battery *battery) { + int power_unit; + if (!battery->bat.dev) return; + power_unit = battery->power_unit; + acpi_battery_get_info(battery); - /* The battery may have changed its reporting units. */ + + if (power_unit == battery->power_unit) + return; + + /* The battery has changed its reporting units. */ sysfs_remove_battery(battery); sysfs_add_battery(battery); }