On 2014年06月12日 14:55, David Rientjes wrote: > 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 <naszar@xxxxx> >> Reference: https://bugzilla.kernel.org/show_bug.cgi?id=75581 >> Cc: stable@xxxxxxxxxxxxxxx >> Signed-off-by: Lan Tianyu <tianyu.lan@xxxxxxxxx> >> --- >> 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 <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) >> @@ -1135,7 +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); > Hi David: Thanks for review. > We're really going to wait up to 20 * 5 = 100ms for acpi_battery_update() > to succeed? No, this depends which retry acpi_battery_update() will succeed. For most machines, there will be no delay. > How are these the numbers that are determined to be optimal > for probing? So far, it depends the return values of executing ACPI methods. If they were failed, the probing would not go further. > >> + retry--; >> + goto retry_get_info; >> + } > > This most certainly could be rewritten as a for-loop and remove the ugly > goto. Ok. I will update. > >> + >> if (result) >> goto fail; >> #ifdef CONFIG_ACPI_PROCFS_POWER -- Best regards Tianyu Lan -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
