Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755769AbaFLGzy (ORCPT ); Thu, 12 Jun 2014 02:55:54 -0400 Received: from mail-ie0-f181.google.com ([209.85.223.181]:44464 "EHLO mail-ie0-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755738AbaFLGzw (ORCPT ); Thu, 12 Jun 2014 02:55:52 -0400 Date: Wed, 11 Jun 2014 23:55:49 -0700 (PDT) From: David Rientjes X-X-Sender: rientjes@chino.kir.corp.google.com To: Lan Tianyu cc: rjw@rjwysocki.net, lenb@kernel.org, naszar@ya.ru, linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH] ACPI/Battery: Retry to get Battery information if failed during probing In-Reply-To: <1402552946-14704-1-git-send-email-tianyu.lan@intel.com> Message-ID: References: <1402552946-14704-1-git-send-email-tianyu.lan@intel.com> User-Agent: Alpine 2.02 (DEB 1266 2009-07-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 12 Jun 2014, Lan Tianyu wrote: > Some machines'(E,G Lenovo Z480) ECs are not stable during boot up > and causes battery driver fails to be probed 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. > > Reported-and-tested-by: naszar > Reference: https://bugzilla.kernel.org/show_bug.cgi?id=75581 > Cc: stable@vger.kernel.org > Signed-off-by: Lan Tianyu > --- > drivers/acpi/battery.c | 12 +++++++++++- > 1 file changed, 11 insertions(+), 1 deletion(-) > > diff --git a/drivers/acpi/battery.c b/drivers/acpi/battery.c > index e48fc98..485009d 100644 > --- a/drivers/acpi/battery.c > +++ b/drivers/acpi/battery.c > @@ -34,6 +34,7 @@ > #include > #include > #include > +#include > #include > > #ifdef CONFIG_ACPI_PROCFS_POWER > @@ -1119,7 +1120,7 @@ static struct dmi_system_id bat_dmi_table[] = { > > static int acpi_battery_add(struct acpi_device *device) > { > - int result = 0; > + int result = 0, retry = 5; > struct acpi_battery *battery = NULL; > > if (!device) > @@ -1135,7 +1136,16 @@ static int acpi_battery_add(struct acpi_device *device) > mutex_init(&battery->sysfs_lock); > if (acpi_has_method(battery->device->handle, "_BIX")) > set_bit(ACPI_BATTERY_XINFO_PRESENT, &battery->flags); > + > +retry_get_info: > result = acpi_battery_update(battery, false); > + > + if (result && retry) { > + msleep(20); We're really going to wait up to 20 * 5 = 100ms for acpi_battery_update() to succeed? How are these the numbers that are determined to be optimal for probing? > + retry--; > + goto retry_get_info; > + } This most certainly could be rewritten as a for-loop and remove the ugly goto. > + > if (result) > goto fail; > #ifdef CONFIG_ACPI_PROCFS_POWER -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/