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 <nas...@ya.ru>
> Reference: https://bugzilla.kernel.org/show_bug.cgi?id=75581
> Cc: <sta...@vger.kernel.org>
> Signed-off-by: Lan Tianyu <tianyu....@intel.com>
> ---
> 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 <linux/dmi.h>
> #include <linux/slab.h>
> #include <linux/suspend.h>
> +#include <linux/delay.h>
> #include <asm/unaligned.h>
>
> #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.
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