The patch below does not apply to the 3.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable@xxxxxxxxxxxxxxx>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 75646e758a0ecbed5024454507d5be5b9ea9dcbf Mon Sep 17 00:00:00 2001 From: Lan Tianyu <tianyu.lan@xxxxxxxxx> Date: Mon, 7 Jul 2014 15:47:12 +0800 Subject: [PATCH] ACPI / battery: Retry to get battery information if failed during probing 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 <naszar@xxxxx> Cc: All applicable <stable@xxxxxxxxxxxxxxx> Signed-off-by: Lan Tianyu <tianyu.lan@xxxxxxxxx> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> diff --git a/drivers/acpi/battery.c b/drivers/acpi/battery.c index 0d7116f34b95..bc0b286ff2ba 100644 --- a/drivers/acpi/battery.c +++ b/drivers/acpi/battery.c @@ -35,6 +35,7 @@ #include <linux/delay.h> #include <linux/slab.h> #include <linux/suspend.h> +#include <linux/delay.h> #include <asm/unaligned.h> #ifdef CONFIG_ACPI_PROCFS_POWER @@ -1151,6 +1152,28 @@ static struct dmi_system_id bat_dmi_table[] = { {}, }; +/* + * 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, false); + if (!ret) + break; + + msleep(20); + } + return ret; +} + static int acpi_battery_add(struct acpi_device *device) { int result = 0; @@ -1169,9 +1192,11 @@ 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); + + result = acpi_battery_update_retry(battery); if (result) goto fail; + #ifdef CONFIG_ACPI_PROCFS_POWER result = acpi_battery_add_fs(device); #endif -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html