On Tuesday, June 17, 2014 06:41:54 PM Josef Gajdusek wrote:
> It seems that some batteries (noticed on DELL JYPJ136) assume
> capacity_now = design_capacity when fully charged. This causes
> reported capacity to suddenly jump to >full_charge_capacity (and that
> means capacity reported to userspace is >100% and incorrect)
> values after 99%. This patch attempts to detect this bug, notifies
> userspace and trims the value to full_charge_capacity.
>
> Signed-off-by: Josef Gajdusek <a...@atx.name>
> ---
> Relaxed the check as you suggested and added printk_once.
>
> > Why don't you use the
> >
> > battery->capacity_now > battery->full_charge_capacity
> >
> > check here? That would be more robust, wouldn't it?
>
> To allow userspace to see that there is some unknown bug we do not know yet
> with the battery. This is taken care of much more elegantly by the printk
> now.
>
> diff --git a/drivers/acpi/battery.c b/drivers/acpi/battery.c
> index e48fc98..57a800c 100644
> --- a/drivers/acpi/battery.c
> +++ b/drivers/acpi/battery.c
> @@ -532,6 +532,18 @@ static int acpi_battery_get_state(struct acpi_battery
> *battery)
> " invalid.\n");
> }
>
> + /* When fully charged, some batteries wrongly report
> + * capacity_now = design_capacity instead of = full_charge_capacity
> + */
> + if (battery->capacity_now > battery->full_charge_capacity) {
But it still is necessary to check if battery->full_charge_capacity is
not ACPI_BATTERY_VALUE_UNKNOWN, isn't it?
> + battery->capacity_now = battery->full_charge_capacity;
> + printk_once(KERN_WARNING FW_BUG
> + "battery: reported current charge level (%d) "
> + "is higher than reported maximum charge level (%d)."
> + "This is normal on some systems.\n",
> + battery->capacity_now, battery->full_charge_capacity);
> + }
> +
> if (test_bit(ACPI_BATTERY_QUIRK_PERCENTAGE_CAPACITY, &battery->flags)
> && battery->capacity_now >= 0 && battery->capacity_now <= 100)
> battery->capacity_now = (battery->capacity_now *
--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
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