From patchwork Mon Oct 27 15:09:44 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [RFC, V2] ACPI: Add _DEP(Operation Region Dependencies) support to fix battery issue on the Asus T100TA From: "lan,Tianyu" X-Patchwork-Id: 5161621 Message-Id: <1414422584-2638-1-git-send-email-tianyu.lan@intel.com> To: rjw@rjwysocki.net, lenb@kernel.org, wsa@the-dreams.de, robert.moore@intel.com, lv.zheng@intel.com Cc: Lan Tianyu , linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, linux-i2c@vger.kernel.org, devel@acpica.org Date: Mon, 27 Oct 2014 23:09:44 +0800 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 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. Signed-off-by: Lan Tianyu --- Change since V1: Rework struct acpi_dep_data, record master and slave's ACPI handle. Rename dep_present with dep_unmet and make it as a count. Increase dep_unmet during bootup and decrease it when associated operation region is installed. drivers/acpi/scan.c | 91 +++++++++++++++++++++++++++++++++++++++++++++++++ drivers/i2c/i2c-core.c | 1 + include/acpi/acpi_bus.h | 1 + include/linux/acpi.h | 3 ++ 4 files changed, 96 insertions(+) diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index 4da55d8..bfa9c77 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; @@ -2121,6 +2129,63 @@ 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; + struct acpi_device_info *info; + acpi_status status; + int i, skip; + + 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++) { + + 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 + */ + if (info->valid & ACPI_VALID_HID + && !strcmp(info->hardware_id.string, "INT3396")) + skip = 1; + else + skip = 0; + + kfree(info); + + if (skip) + continue; + + dep = kzalloc(sizeof(struct acpi_dep_data), GFP_KERNEL); + if (!dep) { + dev_err(&adev->dev, "Not enough memory for _DEP list entry.\n"); + 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) { @@ -2147,6 +2212,7 @@ 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) @@ -2267,6 +2333,31 @@ static void acpi_bus_attach(struct acpi_device *device) device->handler->hotplug.notify_online(device); } +int 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); + + return 0; +} +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 126e182..d5495ca 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -402,6 +402,7 @@ 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 98cd723..269f068 100644 --- a/include/acpi/acpi_bus.h +++ b/include/acpi/acpi_bus.h @@ -367,6 +367,7 @@ 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 2b9c235..cec5f55 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -428,6 +428,7 @@ extern 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); +int acpi_walk_dep_device_list(acpi_handle handle); struct platform_device *acpi_create_platform_device(struct acpi_device *); #define ACPI_PTR(_ptr) (_ptr) @@ -446,6 +447,8 @@ static inline const char *acpi_dev_name(struct acpi_device *adev) static inline void acpi_early_init(void) { } +static inline int acpi_walk_dep_device_list(acpi_handle handle) { } + static inline int early_acpi_boot_init(void) { return 0;