From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753102AbaHDQ6c (ORCPT ); Mon, 4 Aug 2014 12:58:32 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:56583 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752058AbaHDQt5 (ORCPT ); Mon, 4 Aug 2014 12:49:57 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Rafael J. Wysocki" , "Lan Tianyu" Date: Mon, 04 Aug 2014 17:48:32 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.2 37/94] ACPI / battery: Retry to get battery information if failed during probing In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.249 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2.62-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Lan Tianyu commit 75646e758a0ecbed5024454507d5be5b9ea9dcbf upstream. Some machines (eg. Lenovo Z480) ECs are not stable during boot up and causes battery driver fails to be loaded due to failure of getting battery information from EC sometimes. After several retries, the operation will work. This patch is to retry to get battery information 5 times if the first try fails. Link: https://bugzilla.kernel.org/show_bug.cgi?id=75581 Reported-and-tested-by: naszar Signed-off-by: Lan Tianyu Signed-off-by: Rafael J. Wysocki [bwh: Backported to 3.2: acpi_battery_update() doesn't take a second parameter] Signed-off-by: Ben Hutchings --- drivers/acpi/battery.c | 27 ++++++++++++++++++++++++++- 1 file changed, 26 insertions(+), 1 deletion(-) --- a/drivers/acpi/battery.c +++ b/drivers/acpi/battery.c @@ -34,6 +34,7 @@ #include #include #include +#include #include #ifdef CONFIG_ACPI_PROCFS_POWER @@ -1055,6 +1056,28 @@ static int battery_notify(struct notifie return 0; } +/* + * Some machines'(E,G Lenovo Z480) ECs are not stable + * during boot up and this causes battery driver fails to be + * probed due to failure of getting battery information + * from EC sometimes. After several retries, the operation + * may work. So add retry code here and 20ms sleep between + * every retries. + */ +static int acpi_battery_update_retry(struct acpi_battery *battery) +{ + int retry, ret; + + for (retry = 5; retry; retry--) { + ret = acpi_battery_update(battery); + if (!ret) + break; + + msleep(20); + } + return ret; +} + static int acpi_battery_add(struct acpi_device *device) { int result = 0; @@ -1074,9 +1097,11 @@ static int acpi_battery_add(struct acpi_ if (ACPI_SUCCESS(acpi_get_handle(battery->device->handle, "_BIX", &handle))) set_bit(ACPI_BATTERY_XINFO_PRESENT, &battery->flags); - result = acpi_battery_update(battery); + + result = acpi_battery_update_retry(battery); if (result) goto fail; + #ifdef CONFIG_ACPI_PROCFS_POWER result = acpi_battery_add_fs(device); #endif