On Sunday, November 23, 2014 09:22:54 PM Lan Tianyu wrote: > ACPI 5.0 introduces _DEP 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 the 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. > > Reference: https://bugzilla.kernel.org/show_bug.cgi?id=69011 > Tested-by: Jan-Michael Brummer <jan.brummer@xxxxxxxxx> > Tested-by: Adam Williamson <adamw@xxxxxxxxxxxxxxxxx> > Tested-by: Michael Shigorin <shigorin@xxxxxxxxx> > Acked-by: Wolfram Sang <wsa@xxxxxxxxxxxxx> > Acked-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx> > Signed-off-by: Lan Tianyu <tianyu.lan@xxxxxxxxx> Queued up for 3.19-rc1, thanks! > --- > Change since V2: > Coding style change > Change since V1: > Remove redundant blank line and some coding style fixs. > > > drivers/acpi/battery.c | 4 +++ > drivers/acpi/scan.c | 85 +++++++++++++++++++++++++++++++++++++++++++++++++ > drivers/i2c/i2c-core.c | 1 + > include/acpi/acpi_bus.h | 1 + > include/linux/acpi.h | 1 + > 5 files changed, 92 insertions(+) > > diff --git a/drivers/acpi/battery.c b/drivers/acpi/battery.c > index 8ec8a89..d98ba43 100644 > --- a/drivers/acpi/battery.c > +++ b/drivers/acpi/battery.c > @@ -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; > diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c > index 9cb5cca..1b1cf55 100644 > --- a/drivers/acpi/scan.c > +++ b/drivers/acpi/scan.c > @@ -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; > @@ -2193,6 +2201,59 @@ 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) > { > @@ -2219,6 +2280,7 @@ 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) > @@ -2339,6 +2401,29 @@ 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. > diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c > index f43b4e1..68aeb8e 100644 > --- a/drivers/i2c/i2c-core.c > +++ b/drivers/i2c/i2c-core.c > @@ -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; > } > > diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h > index 7d1ce40..d539084 100644 > --- a/include/acpi/acpi_bus.h > +++ b/include/acpi/acpi_bus.h > @@ -372,6 +372,7 @@ 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 *); > diff --git a/include/linux/acpi.h b/include/linux/acpi.h > index 10f2ed9..e09f7f4 100644 > --- a/include/linux/acpi.h > +++ b/include/linux/acpi.h > @@ -428,6 +428,7 @@ extern bool acpi_driver_match_device(struct device *dev, > const struct device_driver *drv); > 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) > -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
