ACPI: Add _DEP support to fix battery issue on Asus T100TA

ACPI 5.0 introduces _DEP (Operation Region Dependencies) to designate
device objects that OSPM should assign a higher priority in start
ordering due to future operation region accesses.

On Asus T100TA, ACPI battery info are read from a I2C slave device via
I2C operation region. Before I2C operation region handler is installed,
battery _STA always returns 0. There is a _DEP method of designating
start order under battery device node.

This patch is to implement _DEP feature to fix battery issue on the
Asus T100TA.  Introducing acpi_dep_list and adding dep_unmet count
in struct acpi_device. During ACPI namespace scan, create struct
acpi_dep_data for a valid pair of master (device pointed to by _DEP)/
slave(device with _DEP), record master's and slave's ACPI handle in
it and put it into acpi_dep_list. The dep_unmet count will increase
by one if there is a device under its _DEP. Driver's probe() should
return EPROBE_DEFER when find dep_unmet is larger than 0. When I2C
operation region handler is installed, remove all struct acpi_dep_data
on the acpi_dep_list whose master is pointed to I2C host controller
and decrease slave's dep_unmet. When dep_unmet decreases to 0, all
_DEP conditions are met and then do acpi_bus_attach() for the device
in order to resolve battery _STA issue on the Asus T100TA.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=69011
Tested-by: Jan-Michael Brummer <jan.brummer@tabos.org>
Tested-by: Adam Williamson <adamw@happyassassin.net>
Tested-by: Michael Shigorin <shigorin@gmail.com>
Acked-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Lan Tianyu 2014-11-23 21:22:54 +08:00 committed by Rafael J. Wysocki
parent 5d01410fe4
commit 40e7fcb192
5 changed files with 92 additions and 0 deletions

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@ -1180,6 +1180,10 @@ static int acpi_battery_add(struct acpi_device *device)
if (!device)
return -EINVAL;
if (device->dep_unmet)
return -EPROBE_DEFER;
battery = kzalloc(sizeof(struct acpi_battery), GFP_KERNEL);
if (!battery)
return -ENOMEM;

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@ -36,6 +36,8 @@ bool acpi_force_hot_remove;
static const char *dummy_hid = "device";
static LIST_HEAD(acpi_dep_list);
static DEFINE_MUTEX(acpi_dep_list_lock);
static LIST_HEAD(acpi_bus_id_list);
static DEFINE_MUTEX(acpi_scan_lock);
static LIST_HEAD(acpi_scan_handlers_list);
@ -43,6 +45,12 @@ DEFINE_MUTEX(acpi_device_lock);
LIST_HEAD(acpi_wakeup_device_list);
static DEFINE_MUTEX(acpi_hp_context_lock);
struct acpi_dep_data {
struct list_head node;
acpi_handle master;
acpi_handle slave;
};
struct acpi_device_bus_id{
char bus_id[15];
unsigned int instance_no;
@ -2086,6 +2094,59 @@ static void acpi_scan_init_hotplug(struct acpi_device *adev)
}
}
static void acpi_device_dep_initialize(struct acpi_device *adev)
{
struct acpi_dep_data *dep;
struct acpi_handle_list dep_devices;
acpi_status status;
int i;
if (!acpi_has_method(adev->handle, "_DEP"))
return;
status = acpi_evaluate_reference(adev->handle, "_DEP", NULL,
&dep_devices);
if (ACPI_FAILURE(status)) {
dev_err(&adev->dev, "Failed to evaluate _DEP.\n");
return;
}
for (i = 0; i < dep_devices.count; i++) {
struct acpi_device_info *info;
int skip;
status = acpi_get_object_info(dep_devices.handles[i], &info);
if (ACPI_FAILURE(status)) {
dev_err(&adev->dev, "Error reading device info\n");
continue;
}
/*
* Skip the dependency of Windows System Power
* Management Controller
*/
skip = info->valid & ACPI_VALID_HID &&
!strcmp(info->hardware_id.string, "INT3396");
kfree(info);
if (skip)
continue;
dep = kzalloc(sizeof(struct acpi_dep_data), GFP_KERNEL);
if (!dep)
return;
dep->master = dep_devices.handles[i];
dep->slave = adev->handle;
adev->dep_unmet++;
mutex_lock(&acpi_dep_list_lock);
list_add_tail(&dep->node , &acpi_dep_list);
mutex_unlock(&acpi_dep_list_lock);
}
}
static acpi_status acpi_bus_check_add(acpi_handle handle, u32 lvl_not_used,
void *not_used, void **return_value)
{
@ -2112,6 +2173,7 @@ static acpi_status acpi_bus_check_add(acpi_handle handle, u32 lvl_not_used,
return AE_CTRL_DEPTH;
acpi_scan_init_hotplug(device);
acpi_device_dep_initialize(device);
out:
if (!*return_value)
@ -2232,6 +2294,29 @@ static void acpi_bus_attach(struct acpi_device *device)
device->handler->hotplug.notify_online(device);
}
void acpi_walk_dep_device_list(acpi_handle handle)
{
struct acpi_dep_data *dep, *tmp;
struct acpi_device *adev;
mutex_lock(&acpi_dep_list_lock);
list_for_each_entry_safe(dep, tmp, &acpi_dep_list, node) {
if (dep->master == handle) {
acpi_bus_get_device(dep->slave, &adev);
if (!adev)
continue;
adev->dep_unmet--;
if (!adev->dep_unmet)
acpi_bus_attach(adev);
list_del(&dep->node);
kfree(dep);
}
}
mutex_unlock(&acpi_dep_list_lock);
}
EXPORT_SYMBOL_GPL(acpi_walk_dep_device_list);
/**
* acpi_bus_scan - Add ACPI device node objects in a given namespace scope.
* @handle: Root of the namespace scope to scan.

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@ -403,6 +403,7 @@ static int acpi_i2c_install_space_handler(struct i2c_adapter *adapter)
return -ENOMEM;
}
acpi_walk_dep_device_list(handle);
return 0;
}

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@ -359,6 +359,7 @@ struct acpi_device {
void *driver_data;
struct device dev;
unsigned int physical_node_count;
unsigned int dep_unmet;
struct list_head physical_node_list;
struct mutex physical_node_lock;
void (*remove)(struct acpi_device *);

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@ -431,6 +431,7 @@ static inline bool acpi_driver_match_device(struct device *dev,
int acpi_device_uevent_modalias(struct device *, struct kobj_uevent_env *);
int acpi_device_modalias(struct device *, char *, int);
void acpi_walk_dep_device_list(acpi_handle handle);
struct platform_device *acpi_create_platform_device(struct acpi_device *);
#define ACPI_PTR(_ptr) (_ptr)