From 55003b2105a4578736f3e868fbaa889bb1ff3ce0 Mon Sep 17 00:00:00 2001 From: Lan Tianyu Date: Thu, 30 Jun 2011 11:33:12 +0800 Subject: [PATCH] ACPI / Battery: Change 16-bit signed negative battery current into correct value This patch is for some machines which report the battery current as a 16-bit signed negative when it is charging. This is caused by DSDT bug. The commit bc76f90b8a5cf4aceedf210d08d5e8292f820cec has resolved the problem for Acer laptops. But some other machines also have such problem. https://bugzilla.kernel.org/show_bug.cgi?id=33722 Since it is improper that the current is above 32A on laptops whether on AC or on battery, this patch is to check the current and take its absolute value as current and producing a message when it is negative in s16. Remove Acer quirk, as this workaround handles Acer too. Signed-off-by: Lan Tianyu Signed-off-by: Len Brown --- drivers/acpi/battery.c | 26 ++++++++++---------------- 1 file changed, 10 insertions(+), 16 deletions(-) diff --git a/drivers/acpi/battery.c b/drivers/acpi/battery.c index 611434f413db..ff1ff70da384 100644 --- a/drivers/acpi/battery.c +++ b/drivers/acpi/battery.c @@ -94,11 +94,6 @@ MODULE_DEVICE_TABLE(acpi, battery_device_ids); enum { ACPI_BATTERY_ALARM_PRESENT, ACPI_BATTERY_XINFO_PRESENT, - /* For buggy DSDTs that report negative 16-bit values for either - * charging or discharging current and/or report 0 as 65536 - * due to bad math. - */ - ACPI_BATTERY_QUIRK_SIGNED16_CURRENT, ACPI_BATTERY_QUIRK_PERCENTAGE_CAPACITY, }; @@ -465,9 +460,17 @@ static int acpi_battery_get_state(struct acpi_battery *battery) battery->update_time = jiffies; kfree(buffer.pointer); - if (test_bit(ACPI_BATTERY_QUIRK_SIGNED16_CURRENT, &battery->flags) && - battery->rate_now != -1) + /* For buggy DSDTs that report negative 16-bit values for either + * charging or discharging current and/or report 0 as 65536 + * due to bad math. + */ + if (battery->power_unit == ACPI_BATTERY_POWER_UNIT_MA && + battery->rate_now != ACPI_BATTERY_VALUE_UNKNOWN && + (s16)(battery->rate_now) < 0) { battery->rate_now = abs((s16)battery->rate_now); + printk_once(KERN_WARNING FW_BUG "battery: (dis)charge rate" + " invalid.\n"); + } if (test_bit(ACPI_BATTERY_QUIRK_PERCENTAGE_CAPACITY, &battery->flags) && battery->capacity_now >= 0 && battery->capacity_now <= 100) @@ -577,14 +580,6 @@ static void sysfs_remove_battery(struct acpi_battery *battery) battery->bat.dev = NULL; } -static void acpi_battery_quirks(struct acpi_battery *battery) -{ - if (dmi_name_in_vendors("Acer") && - battery->power_unit == ACPI_BATTERY_POWER_UNIT_MA) { - set_bit(ACPI_BATTERY_QUIRK_SIGNED16_CURRENT, &battery->flags); - } -} - /* * According to the ACPI spec, some kinds of primary batteries can * report percentage battery remaining capacity directly to OS. @@ -628,7 +623,6 @@ static int acpi_battery_update(struct acpi_battery *battery) result = acpi_battery_get_info(battery); if (result) return result; - acpi_battery_quirks(battery); acpi_battery_init_alarm(battery); } if (!battery->bat.dev)