From cd0c28d2281c65aa0ae89be80abcbf8e21c885b4 Mon Sep 17 00:00:00 2001 From: Lan Tianyu Date: Mon, 7 Jul 2014 15:47:12 +0800 Subject: ACPI / battery: Retry to get battery information if failed during probing 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. [ backport to 3.14.5: removed second parameter in acpi_battery_update(), introduced by the commit 9e50bc14a7f58b5d8a55973b2d69355852ae2dae (ACPI / battery: Accelerate battery resume callback)] [naszar : backport to 3.14.5] Link: https://bugzilla.kernel.org/show_bug.cgi?id=75581 Reported-and-tested-by: naszar Cc: All applicable Signed-off-by: Lan Tianyu Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman --- drivers/acpi/battery.c | 27 ++++++++++++++++++++++++++- 1 file changed, 26 insertions(+), 1 deletion(-) diff --git a/drivers/acpi/battery.c b/drivers/acpi/battery.c index 9bdfcf50a19..93f3034ea85 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 @@ -1055,6 +1056,28 @@ static int battery_notify(struct notifier_block *nb, 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_device *device) 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 -- cgit v1.2.3-18-g5258