Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755725AbaFQLR5 (ORCPT ); Tue, 17 Jun 2014 07:17:57 -0400 Received: from v094114.home.net.pl ([79.96.170.134]:59264 "HELO v094114.home.net.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1752082AbaFQLRy (ORCPT ); Tue, 17 Jun 2014 07:17:54 -0400 From: "Rafael J. Wysocki" To: Lan Tianyu Cc: lenb@kernel.org, naszar@ya.ru, rientjes@google.com, linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH V2] ACPI/Battery: Retry to get Battery information if failed during probing Date: Tue, 17 Jun 2014 13:35:27 +0200 Message-ID: <1474004.fDjayHqHT9@vostro.rjw.lan> User-Agent: KMail/4.11.5 (Linux/3.15.0-rc5+; KDE/4.11.5; x86_64; ; ) In-Reply-To: <1402988994-27067-1-git-send-email-tianyu.lan@intel.com> References: <1402988994-27067-1-git-send-email-tianyu.lan@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="utf-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tuesday, June 17, 2014 03:09:54 PM Lan Tianyu wrote: > Some machines'(E,G 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. > > Reported-and-tested-by: naszar > Reference: https://bugzilla.kernel.org/show_bug.cgi?id=75581 > Cc: > Signed-off-by: Lan Tianyu > --- > Change since V2: > Change code style and add comment. > > drivers/acpi/battery.c | 16 ++++++++++++++-- > 1 file changed, 14 insertions(+), 2 deletions(-) > > diff --git a/drivers/acpi/battery.c b/drivers/acpi/battery.c > index e48fc98..8ed93a3 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) > @@ -1135,9 +1136,20 @@ 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); > - result = acpi_battery_update(battery, false); > + > + /* > + * 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. > + */ > + while ((result = acpi_battery_update(battery, false)) && retry--) > + msleep(20); > if (result) > goto fail; Why not to write this as for (;;) { result = acpi_battery_update(battery, false); if (!result) break; else if (!--retry) goto fail; msleep(20); } > + > #ifdef CONFIG_ACPI_PROCFS_POWER > result = acpi_battery_add_fs(device); > #endif > -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. -- 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/