On Sunday 28 October 2007, Andrey Borzenkov wrote: > On Saturday 27 October 2007, Anton Vorontsov wrote: > > On Sat, Oct 27, 2007 at 08:54:30PM +0400, Andrey Borzenkov wrote: > > > I am not exactly sure about this one ... what other power_supply class > > > drivers do? Should I fix HAL instead (but then, I do not know whether > > > HAL is the only application that is using this interface). > > > > Well, PROP_PRESENT wasn't my idea, currently it's used by pmu and > > olpc drivers becuase it's not trivial to register/unregister their > > batteries on physical insertion/removal. I have some plans to teach > > at least pmu batteries to not use PROP_PRESENT. I don't have any > > OLPC, thus I can't convert it. > > > > To sum this: the good way to handle "missing" batteries is to > > unregister them, so they'll not show up in the /sys/class/power_supply. > > Well, in this case HAL behaviour makes sense (default to present == true > if "present" attribute is missing) > > > Is that possible with the ACPI? > > At least looking in ACPI specs, this looks possible. What currently is > presented as battery object is actually battery bay according to ACPI spec: > > Unlike most other devices, when a battery is inserted or removed from the > system, the device itself (the > battery bay) is still considered to be present in the system. > > When battery is inserted/removed, ACPI notifies us and we can check whether > battery is actually present and update registration accordingly. From the > sysfs structure POV probably nothing has to be changed; just when and how > power_supply is registered > under /sys/devices/LNXSYSTM:00/device:00/PNP0C0A:0n > > Alexey, does it make sense (or doable)? or would you take attached patch as prototype? :) This works on my system and does not crash it immediately. Here is event sequence I get: UEVENT[1193556388.161539] add /module/battery (module) ACTION=add DEVPATH=/module/battery SUBSYSTEM=module SEQNUM=3243 UEVENT[1193556388.177069] add /bus/acpi/drivers/battery (drivers) ACTION=add DEVPATH=/bus/acpi/drivers/battery SUBSYSTEM=drivers SEQNUM=3244 UEVENT[1193556388.212721] add /devices/LNXSYSTM:00/device:00/PNP0C0A:00/power_supply/BAT1 (power_supply) ACTION=add DEVPATH=/devices/LNXSYSTM:00/device:00/PNP0C0A:00/power_supply/BAT1 SUBSYSTEM=power_supply SEQNUM=3245 UEVENT[1193556388.223113] change /devices/LNXSYSTM:00/device:00/PNP0C0A:00/power_supply/BAT1 (power_supply) ACTION=change DEVPATH=/devices/LNXSYSTM:00/device:00/PNP0C0A:00/power_supply/BAT1 SUBSYSTEM=power_supply POWER_SUPPLY_NAME=BAT1 POWER_SUPPLY_TYPE=Battery POWER_SUPPLY_STATUS=Full POWER_SUPPLY_PRESENT=1 POWER_SUPPLY_TECHNOLOGY=Unknown POWER_SUPPLY_VOLTAGE_MIN_DESIGN=10800000 POWER_SUPPLY_VOLTAGE_NOW=0 POWER_SUPPLY_CURRENT_NOW=0 POWER_SUPPLY_ENERGY_FULL_DESIGN=38880000 POWER_SUPPLY_ENERGY_FULL=37530000 POWER_SUPPLY_ENERGY_NOW=0 POWER_SUPPLY_MODEL_NAME=XM2038P04 POWER_SUPPLY_MANUFACTURER= SEQNUM=3246 physically remove battery UEVENT[1193556483.326303] remove /devices/LNXSYSTM:00/device:00/PNP0C0A:00/power_supply/BAT1 (power_supply) ACTION=remove DEVPATH=/devices/LNXSYSTM:00/device:00/PNP0C0A:00/power_supply/BAT1 SUBSYSTEM=power_supply POWER_SUPPLY_NAME=BAT1 POWER_SUPPLY_TYPE=Battery POWER_SUPPLY_PRESENT=0 SEQNUM=3252 battery back UEVENT[1193556510.339045] add /devices/LNXSYSTM:00/device:00/PNP0C0A:00/power_supply/BAT1 (power_supply) ACTION=add DEVPATH=/devices/LNXSYSTM:00/device:00/PNP0C0A:00/power_supply/BAT1 SUBSYSTEM=power_supply SEQNUM=3253 UEVENT[1193556510.339387] change /devices/LNXSYSTM:00/device:00/PNP0C0A:00/power_supply/BAT1 (power_supply) ACTION=change DEVPATH=/devices/LNXSYSTM:00/device:00/PNP0C0A:00/power_supply/BAT1 SUBSYSTEM=power_supply POWER_SUPPLY_NAME=BAT1 POWER_SUPPLY_TYPE=Battery POWER_SUPPLY_STATUS=Charging POWER_SUPPLY_PRESENT=1 POWER_SUPPLY_TECHNOLOGY=Unknown POWER_SUPPLY_VOLTAGE_MIN_DESIGN=10800000 POWER_SUPPLY_VOLTAGE_NOW=11340000 POWER_SUPPLY_CURRENT_NOW=13197000 POWER_SUPPLY_ENERGY_FULL_DESIGN=38880000 POWER_SUPPLY_ENERGY_FULL=37530000 POWER_SUPPLY_ENERGY_NOW=37519000 POWER_SUPPLY_MODEL_NAME=XM2038P04 POWER_SUPPLY_MANUFACTURER= SEQNUM=3254 We'll probably need to teach user space to distinguish between battery and battery bay (and not to crash when battery is removed :) ) but that is all doable once we settle on kernel implementation.
Subject: [PATCH] [2.6.24-rc] ACPI: register power_supply subdevice only when battery is present From: Andrey Borzenkov <[email protected]> Make sure no power_supply object is present unless we actualy detect presence of battery. This fixes ghost batteries detected by HAL Signed-off-by: Andrey Borzenkov <[email protected]> --- drivers/acpi/battery.c | 98 ++++++++++++++++++++++++++++++------------------ 1 files changed, 61 insertions(+), 37 deletions(-) diff --git a/drivers/acpi/battery.c b/drivers/acpi/battery.c index d33cb49..f37e509 100644 --- a/drivers/acpi/battery.c +++ b/drivers/acpi/battery.c @@ -390,14 +390,64 @@ static int acpi_battery_init_alarm(struct acpi_battery *battery) return acpi_battery_set_alarm(battery); } +static ssize_t acpi_battery_alarm_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct acpi_battery *battery = to_acpi_battery(dev_get_drvdata(dev)); + return sprintf(buf, "%d\n", battery->alarm * 1000); +} + +static ssize_t acpi_battery_alarm_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + unsigned long x; + struct acpi_battery *battery = to_acpi_battery(dev_get_drvdata(dev)); + if (sscanf(buf, "%ld\n", &x) == 1) + battery->alarm = x/1000; + if (acpi_battery_present(battery)) + acpi_battery_set_alarm(battery); + return count; +} + +static struct device_attribute alarm_attr = { + .attr = {.name = "alarm", .mode = 0644, .owner = THIS_MODULE}, + .show = acpi_battery_alarm_show, + .store = acpi_battery_alarm_store, +}; + +static int sysfs_add_battery(struct acpi_battery *battery) +{ + int result = 0; + + result = power_supply_register(&battery->device->dev, &battery->bat); + result = device_create_file(battery->bat.dev, &alarm_attr); + + return result; +} + +static int sysfs_remove_battery(struct acpi_battery *battery) +{ + if (battery->bat.dev) { + device_remove_file(battery->bat.dev, &alarm_attr); + power_supply_unregister(&battery->bat); + battery->bat.dev = NULL; + } + + return 0; +} + static int acpi_battery_update(struct acpi_battery *battery) { - int saved_present = acpi_battery_present(battery); int result = acpi_battery_get_status(battery); - if (result || !acpi_battery_present(battery)) + if (result) return result; - if (saved_present != acpi_battery_present(battery) || - !battery->update_time) { + if (!acpi_battery_present(battery)) { + sysfs_remove_battery(battery); + return 0; + } + if (!battery->bat.dev) { battery->update_time = 0; result = acpi_battery_get_info(battery); if (result) @@ -411,6 +461,7 @@ static int acpi_battery_update(struct acpi_battery *battery) battery->bat.num_properties = ARRAY_SIZE(energy_battery_props); } + sysfs_add_battery(battery); acpi_battery_init_alarm(battery); } return acpi_battery_get_state(battery); @@ -693,33 +744,6 @@ static void acpi_battery_remove_fs(struct acpi_device *device) #endif -static ssize_t acpi_battery_alarm_show(struct device *dev, - struct device_attribute *attr, - char *buf) -{ - struct acpi_battery *battery = to_acpi_battery(dev_get_drvdata(dev)); - return sprintf(buf, "%d\n", battery->alarm * 1000); -} - -static ssize_t acpi_battery_alarm_store(struct device *dev, - struct device_attribute *attr, - const char *buf, size_t count) -{ - unsigned long x; - struct acpi_battery *battery = to_acpi_battery(dev_get_drvdata(dev)); - if (sscanf(buf, "%ld\n", &x) == 1) - battery->alarm = x/1000; - if (acpi_battery_present(battery)) - acpi_battery_set_alarm(battery); - return count; -} - -static struct device_attribute alarm_attr = { - .attr = {.name = "alarm", .mode = 0644, .owner = THIS_MODULE}, - .show = acpi_battery_alarm_show, - .store = acpi_battery_alarm_store, -}; - /* -------------------------------------------------------------------------- Driver Interface -------------------------------------------------------------------------- */ @@ -737,7 +761,9 @@ static void acpi_battery_notify(acpi_handle handle, u32 event, void *data) acpi_bus_generate_netlink_event(device->pnp.device_class, device->dev.bus_id, event, acpi_battery_present(battery)); - kobject_uevent(&battery->bat.dev->kobj, KOBJ_CHANGE); + /* acpi_batter_update could remove power_supply object */ + if (battery->bat.dev) + kobject_uevent(&battery->bat.dev->kobj, KOBJ_CHANGE); } static int acpi_battery_add(struct acpi_device *device) @@ -755,17 +781,15 @@ static int acpi_battery_add(struct acpi_device *device) strcpy(acpi_device_class(device), ACPI_BATTERY_CLASS); acpi_driver_data(device) = battery; mutex_init(&battery->lock); + battery->bat.name = acpi_device_bid(device); + battery->bat.type = POWER_SUPPLY_TYPE_BATTERY; + battery->bat.get_property = acpi_battery_get_property; acpi_battery_update(battery); #ifdef CONFIG_ACPI_PROCFS result = acpi_battery_add_fs(device); if (result) goto end; #endif - battery->bat.name = acpi_device_bid(device); - battery->bat.type = POWER_SUPPLY_TYPE_BATTERY; - battery->bat.get_property = acpi_battery_get_property; - result = power_supply_register(&battery->device->dev, &battery->bat); - result = device_create_file(battery->bat.dev, &alarm_attr); status = acpi_install_notify_handler(device->handle, ACPI_ALL_NOTIFY, acpi_battery_notify, battery);
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- References:
- [PATCH] 2.6.24-rc1: ensure "present" sysfs attribute even if battery is absent
- From: Andrey Borzenkov <[email protected]>
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- From: Anton Vorontsov <[email protected]>
- Re: [PATCH] 2.6.24-rc1: ensure "present" sysfs attribute even if battery is absent
- From: Andrey Borzenkov <[email protected]>
- [PATCH] 2.6.24-rc1: ensure "present" sysfs attribute even if battery is absent
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