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 detects capacity_now > full_charge_capacity,
notifies userspace (unless it is the known bug where capacity_now ==
design_capacity) and trims the value to full_charge_capacity.
Signed-off-by: Josef Gajdusek <a...@atx.name>
---
> Thinking more about the printk_once(). Perhaps it only needs to be printed
> when battery->capacity_now != battery->design_capacity (it's a known issue
> otherwise).
Changed. That was actually what I wanted to do originally, but I was unsure
about the kernel policy on this sort of messages.
>> + 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",
>
> Also I think that the line above doesn't add any real value. :-)
Removed, now it really is not needed as there is not any known system for which
capacity_now > full_charge_capacity && capacity_now != design_capacity would be
considered "normal"
diff --git a/drivers/acpi/battery.c b/drivers/acpi/battery.c
index e48fc98..9cacabd 100644
--- a/drivers/acpi/battery.c
+++ b/drivers/acpi/battery.c
@@ -532,6 +532,19 @@ 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 &&
+ battery->full_charge_capacity != ACPI_BATTERY_VALUE_UNKNOWN) {
+ battery->capacity_now = battery->full_charge_capacity;
+ if (battery->capacity_now != battery->design_capacity)
+ printk_once(KERN_WARNING FW_BUG
+ "battery: reported current charge level (%d) "
+ "is higher than reported maximum charge level
(%d).\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 *
--
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