From b340c7d6f619ad63d1896a6debceea1de3a78f29 Mon Sep 17 00:00:00 2001 From: Sakari Ailus Date: Mon, 18 Oct 2021 15:17:24 +0300 Subject: [PATCH 1/7] ACPI: scan: Obtain device's desired enumeration power state Store a device's desired enumeration power state in struct acpi_device_power during acpi_device object's initialisation. Signed-off-by: Sakari Ailus Signed-off-by: Rafael J. Wysocki --- drivers/acpi/scan.c | 4 ++++ include/acpi/acpi_bus.h | 1 + 2 files changed, 5 insertions(+) diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index dce2c291b982b..a50f1967c73dc 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -1017,6 +1017,7 @@ static void acpi_bus_init_power_state(struct acpi_device *device, int state) static void acpi_bus_get_power_flags(struct acpi_device *device) { + unsigned long long dsc = ACPI_STATE_D0; u32 i; /* Presence of _PS0|_PR0 indicates 'power manageable' */ @@ -1038,6 +1039,9 @@ static void acpi_bus_get_power_flags(struct acpi_device *device) if (acpi_has_method(device->handle, "_DSW")) device->power.flags.dsw_present = 1; + acpi_evaluate_integer(device->handle, "_DSC", NULL, &dsc); + device->power.state_for_enumeration = dsc; + /* * Enumerate supported power management states */ diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h index 53b6e9f9de7b4..480f9207a4c6b 100644 --- a/include/acpi/acpi_bus.h +++ b/include/acpi/acpi_bus.h @@ -278,6 +278,7 @@ struct acpi_device_power { int state; /* Current state */ struct acpi_device_power_flags flags; struct acpi_device_power_state states[ACPI_D_STATE_COUNT]; /* Power states (D0-D3Cold) */ + u8 state_for_enumeration; /* Deepest power state for enumeration */ }; struct acpi_dep_data { From b18c1ad685d9a6af5189d4cc037a653270a07b4c Mon Sep 17 00:00:00 2001 From: Sakari Ailus Date: Mon, 18 Oct 2021 15:17:25 +0300 Subject: [PATCH 2/7] i2c: Allow an ACPI driver to manage the device's power state during probe Enable drivers to tell ACPI that there's no need to power on a device for probe. Drivers should still perform this by themselves if there's a need to. In some cases powering on the device during probe is undesirable, and this change enables a driver to choose what fits best for it. Add a field called "flags" into struct i2c_driver for driver flags, and a flag I2C_DRV_ACPI_WAIVE_D0_PROBE to tell a driver supports probe in ACPI D states other than 0. Signed-off-by: Sakari Ailus Reviewed-by: Tomasz Figa Acked-by: Wolfram Sang Signed-off-by: Rafael J. Wysocki --- drivers/i2c/i2c-core-acpi.c | 10 ++++++++++ drivers/i2c/i2c-core-base.c | 7 ++++--- include/linux/i2c.h | 18 ++++++++++++++++++ 3 files changed, 32 insertions(+), 3 deletions(-) diff --git a/drivers/i2c/i2c-core-acpi.c b/drivers/i2c/i2c-core-acpi.c index 546cc935e035a..c025919cdaaee 100644 --- a/drivers/i2c/i2c-core-acpi.c +++ b/drivers/i2c/i2c-core-acpi.c @@ -526,6 +526,16 @@ struct i2c_client *i2c_acpi_new_device(struct device *dev, int index, } EXPORT_SYMBOL_GPL(i2c_acpi_new_device); +bool i2c_acpi_waive_d0_probe(struct device *dev) +{ + struct i2c_driver *driver = to_i2c_driver(dev->driver); + struct acpi_device *adev = ACPI_COMPANION(dev); + + return driver->flags & I2C_DRV_ACPI_WAIVE_D0_PROBE && + adev && adev->power.state_for_enumeration >= adev->power.state; +} +EXPORT_SYMBOL_GPL(i2c_acpi_waive_d0_probe); + #ifdef CONFIG_ACPI_I2C_OPREGION static int acpi_gsb_i2c_read_bytes(struct i2c_client *client, u8 cmd, u8 *data, u8 data_len) diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c index 54964fbe3f033..f193f90585841 100644 --- a/drivers/i2c/i2c-core-base.c +++ b/drivers/i2c/i2c-core-base.c @@ -551,7 +551,8 @@ static int i2c_device_probe(struct device *dev) if (status < 0) goto err_clear_wakeup_irq; - status = dev_pm_domain_attach(&client->dev, true); + status = dev_pm_domain_attach(&client->dev, + !i2c_acpi_waive_d0_probe(dev)); if (status) goto err_clear_wakeup_irq; @@ -590,7 +591,7 @@ static int i2c_device_probe(struct device *dev) err_release_driver_resources: devres_release_group(&client->dev, client->devres_group_id); err_detach_pm_domain: - dev_pm_domain_detach(&client->dev, true); + dev_pm_domain_detach(&client->dev, !i2c_acpi_waive_d0_probe(dev)); err_clear_wakeup_irq: dev_pm_clear_wake_irq(&client->dev); device_init_wakeup(&client->dev, false); @@ -621,7 +622,7 @@ static void i2c_device_remove(struct device *dev) devres_release_group(&client->dev, client->devres_group_id); - dev_pm_domain_detach(&client->dev, true); + dev_pm_domain_detach(&client->dev, !i2c_acpi_waive_d0_probe(dev)); if (!pm_runtime_status_suspended(&client->dev) && adap->bus_regulator) regulator_disable(adap->bus_regulator); diff --git a/include/linux/i2c.h b/include/linux/i2c.h index 2ce3efbe9198a..16119ac1aa97e 100644 --- a/include/linux/i2c.h +++ b/include/linux/i2c.h @@ -11,6 +11,7 @@ #define _LINUX_I2C_H #include /* for acpi_handle */ +#include #include #include /* for struct device */ #include /* for completion */ @@ -222,6 +223,15 @@ enum i2c_alert_protocol { I2C_PROTOCOL_SMBUS_HOST_NOTIFY, }; +/** + * enum i2c_driver_flags - Flags for an I2C device driver + * + * @I2C_DRV_ACPI_WAIVE_D0_PROBE: Don't put the device in D0 state for probe + */ +enum i2c_driver_flags { + I2C_DRV_ACPI_WAIVE_D0_PROBE = BIT(0), +}; + /** * struct i2c_driver - represent an I2C device driver * @class: What kind of i2c device we instantiate (for detect) @@ -236,6 +246,7 @@ enum i2c_alert_protocol { * @detect: Callback for device detection * @address_list: The I2C addresses to probe (for detect) * @clients: List of detected clients we created (for i2c-core use only) + * @flags: A bitmask of flags defined in &enum i2c_driver_flags * * The driver.owner field should be set to the module owner of this driver. * The driver.name field should be set to the name of this driver. @@ -294,6 +305,8 @@ struct i2c_driver { int (*detect)(struct i2c_client *client, struct i2c_board_info *info); const unsigned short *address_list; struct list_head clients; + + u32 flags; }; #define to_i2c_driver(d) container_of(d, struct i2c_driver, driver) @@ -1015,6 +1028,7 @@ u32 i2c_acpi_find_bus_speed(struct device *dev); struct i2c_client *i2c_acpi_new_device(struct device *dev, int index, struct i2c_board_info *info); struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle); +bool i2c_acpi_waive_d0_probe(struct device *dev); #else static inline bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares, struct acpi_resource_i2c_serialbus **i2c) @@ -1038,6 +1052,10 @@ static inline struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle ha { return NULL; } +static inline bool i2c_acpi_waive_d0_probe(struct device *dev) +{ + return false; +} #endif /* CONFIG_ACPI */ #endif /* _LINUX_I2C_H */ From ed66f12ba4b17c66b4c59df76d3b1bb2cb3a75d1 Mon Sep 17 00:00:00 2001 From: Sakari Ailus Date: Mon, 18 Oct 2021 15:17:26 +0300 Subject: [PATCH 3/7] Documentation: ACPI: Document _DSC object usage for enum power state Document the use of the _DSC object for setting desirable power state during probe. Signed-off-by: Sakari Ailus Reviewed-by: Tomasz Figa Signed-off-by: Rafael J. Wysocki --- Documentation/firmware-guide/acpi/index.rst | 1 + .../firmware-guide/acpi/non-d0-probe.rst | 78 +++++++++++++++++++ 2 files changed, 79 insertions(+) create mode 100644 Documentation/firmware-guide/acpi/non-d0-probe.rst diff --git a/Documentation/firmware-guide/acpi/index.rst b/Documentation/firmware-guide/acpi/index.rst index a99ee402b212b..b053b0c3d6969 100644 --- a/Documentation/firmware-guide/acpi/index.rst +++ b/Documentation/firmware-guide/acpi/index.rst @@ -26,5 +26,6 @@ ACPI Support acpi-lid lpit video_extension + non-d0-probe extcon-intel-int3496 intel-pmc-mux diff --git a/Documentation/firmware-guide/acpi/non-d0-probe.rst b/Documentation/firmware-guide/acpi/non-d0-probe.rst new file mode 100644 index 0000000000000..78781e1ab6a3d --- /dev/null +++ b/Documentation/firmware-guide/acpi/non-d0-probe.rst @@ -0,0 +1,78 @@ +.. SPDX-License-Identifier: GPL-2.0 + +======================================== +Probing devices in other D states than 0 +======================================== + +Introduction +============ + +In some cases it may be preferred to leave certain devices powered off for the +entire system bootup if powering on these devices has adverse side effects, +beyond just powering on the said device. + +How it works +============ + +The _DSC (Device State for Configuration) object that evaluates to an integer +may be used to tell Linux the highest allowed D state for a device during +probe. The support for _DSC requires support from the kernel bus type if the +bus driver normally sets the device in D0 state for probe. + +The downside of using _DSC is that as the device is not powered on, even if +there's a problem with the device, the driver likely probes just fine but the +first user will find out the device doesn't work, instead of a failure at probe +time. This feature should thus be used sparingly. + +I²C +--- + +If an I²C driver indicates its support for this by setting the +I2C_DRV_ACPI_WAIVE_D0_PROBE flag in struct i2c_driver.flags field and the +_DSC object evaluates to integer higher than the D state of the device, +the device will not be powered on (put in D0 state) for probe. + +D states +-------- + +The D states and thus also the allowed values for _DSC are listed below. Refer +to [1] for more information on device power states. + +.. code-block:: text + + Number State Description + 0 D0 Device fully powered on + 1 D1 + 2 D2 + 3 D3hot + 4 D3cold Off + +References +========== + +[1] https://uefi.org/specifications/ACPI/6.4/02_Definition_of_Terms/Definition_of_Terms.html#device-power-state-definitions + +Example +======= + +An ASL example describing an ACPI device using _DSC object to tell Operating +System the device should remain powered off during probe looks like this. Some +objects not relevant from the example point of view have been omitted. + +.. code-block:: text + + Device (CAM0) + { + Name (_HID, "SONY319A") + Name (_UID, Zero) + Name (_CRS, ResourceTemplate () + { + I2cSerialBus(0x0020, ControllerInitiated, 0x00061A80, + AddressingMode7Bit, "\\_SB.PCI0.I2C0", + 0x00, ResourceConsumer) + }) + Name (_DSC, 0, NotSerialized) + { + Return (0x4) + } + } From b82a7df4a7f3841896aaec1ad81e654bc87b5989 Mon Sep 17 00:00:00 2001 From: Sakari Ailus Date: Mon, 18 Oct 2021 15:17:27 +0300 Subject: [PATCH 4/7] ACPI: Add a convenience function to tell a device is in D0 state Add a convenience function to tell whether a device is in D0 state, primarily for use in drivers' probe or remove functions on busses where the custom is to power on the device for the duration of both. Returns false on non-ACPI systems. Suggested-by: Mika Westerberg Signed-off-by: Sakari Ailus Reviewed-by: Tomasz Figa Signed-off-by: Rafael J. Wysocki --- drivers/acpi/device_pm.c | 26 ++++++++++++++++++++++++++ include/linux/acpi.h | 5 +++++ 2 files changed, 31 insertions(+) diff --git a/drivers/acpi/device_pm.c b/drivers/acpi/device_pm.c index 0028b6b51c877..19b33c028f356 100644 --- a/drivers/acpi/device_pm.c +++ b/drivers/acpi/device_pm.c @@ -1400,4 +1400,30 @@ bool acpi_storage_d3(struct device *dev) } EXPORT_SYMBOL_GPL(acpi_storage_d3); +/** + * acpi_dev_state_d0 - Tell if the device is in D0 power state + * @dev: Physical device the ACPI power state of which to check + * + * On a system without ACPI, return true. On a system with ACPI, return true if + * the current ACPI power state of the device is D0, or false otherwise. + * + * Note that the power state of a device is not well-defined after it has been + * passed to acpi_device_set_power() and before that function returns, so it is + * not valid to ask for the ACPI power state of the device in that time frame. + * + * This function is intended to be used in a driver's probe or remove + * function. See Documentation/firmware-guide/acpi/low-power-probe.rst for + * more information. + */ +bool acpi_dev_state_d0(struct device *dev) +{ + struct acpi_device *adev = ACPI_COMPANION(dev); + + if (!adev) + return true; + + return adev->power.state == ACPI_STATE_D0; +} +EXPORT_SYMBOL_GPL(acpi_dev_state_d0); + #endif /* CONFIG_PM */ diff --git a/include/linux/acpi.h b/include/linux/acpi.h index fbc2146050a4e..df70fc27afd75 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -1016,6 +1016,7 @@ int acpi_subsys_runtime_suspend(struct device *dev); int acpi_subsys_runtime_resume(struct device *dev); int acpi_dev_pm_attach(struct device *dev, bool power_on); bool acpi_storage_d3(struct device *dev); +bool acpi_dev_state_d0(struct device *dev); #else static inline int acpi_subsys_runtime_suspend(struct device *dev) { return 0; } static inline int acpi_subsys_runtime_resume(struct device *dev) { return 0; } @@ -1027,6 +1028,10 @@ static inline bool acpi_storage_d3(struct device *dev) { return false; } +static inline bool acpi_dev_state_d0(struct device *dev) +{ + return true; +} #endif #if defined(CONFIG_ACPI) && defined(CONFIG_PM_SLEEP) From 434aa74bd770bc1a712c8431919eabe490dbe707 Mon Sep 17 00:00:00 2001 From: Rajmohan Mani Date: Mon, 18 Oct 2021 15:17:28 +0300 Subject: [PATCH 5/7] media: i2c: imx319: Support device probe in non-zero ACPI D state Tell ACPI device PM code that the driver supports the device being in non-zero ACPI D state when the driver's probe function is entered. Signed-off-by: Rajmohan Mani Signed-off-by: Sakari Ailus Reviewed-by: Tomasz Figa Reviewed-by: Bingbu Cao Signed-off-by: Rafael J. Wysocki --- drivers/media/i2c/imx319.c | 74 ++++++++++++++++++++++---------------- 1 file changed, 44 insertions(+), 30 deletions(-) diff --git a/drivers/media/i2c/imx319.c b/drivers/media/i2c/imx319.c index dba0854ab5aad..daa976858e296 100644 --- a/drivers/media/i2c/imx319.c +++ b/drivers/media/i2c/imx319.c @@ -140,6 +140,8 @@ struct imx319 { /* Streaming on/off */ bool streaming; + /* True if the device has been identified */ + bool identified; }; static const struct imx319_reg imx319_global_regs[] = { @@ -2084,6 +2086,31 @@ imx319_set_pad_format(struct v4l2_subdev *sd, return 0; } +/* Verify chip ID */ +static int imx319_identify_module(struct imx319 *imx319) +{ + struct i2c_client *client = v4l2_get_subdevdata(&imx319->sd); + int ret; + u32 val; + + if (imx319->identified) + return 0; + + ret = imx319_read_reg(imx319, IMX319_REG_CHIP_ID, 2, &val); + if (ret) + return ret; + + if (val != IMX319_CHIP_ID) { + dev_err(&client->dev, "chip id mismatch: %x!=%x", + IMX319_CHIP_ID, val); + return -EIO; + } + + imx319->identified = true; + + return 0; +} + /* Start streaming */ static int imx319_start_streaming(struct imx319 *imx319) { @@ -2091,6 +2118,10 @@ static int imx319_start_streaming(struct imx319 *imx319) const struct imx319_reg_list *reg_list; int ret; + ret = imx319_identify_module(imx319); + if (ret) + return ret; + /* Global Setting */ reg_list = &imx319_global_setting; ret = imx319_write_regs(imx319, reg_list->regs, reg_list->num_of_regs); @@ -2206,26 +2237,6 @@ static int __maybe_unused imx319_resume(struct device *dev) return ret; } -/* Verify chip ID */ -static int imx319_identify_module(struct imx319 *imx319) -{ - struct i2c_client *client = v4l2_get_subdevdata(&imx319->sd); - int ret; - u32 val; - - ret = imx319_read_reg(imx319, IMX319_REG_CHIP_ID, 2, &val); - if (ret) - return ret; - - if (val != IMX319_CHIP_ID) { - dev_err(&client->dev, "chip id mismatch: %x!=%x", - IMX319_CHIP_ID, val); - return -EIO; - } - - return 0; -} - static const struct v4l2_subdev_core_ops imx319_subdev_core_ops = { .subscribe_event = v4l2_ctrl_subdev_subscribe_event, .unsubscribe_event = v4l2_event_subdev_unsubscribe, @@ -2420,6 +2431,7 @@ static struct imx319_hwcfg *imx319_get_hwcfg(struct device *dev) static int imx319_probe(struct i2c_client *client) { struct imx319 *imx319; + bool full_power; int ret; u32 i; @@ -2432,11 +2444,14 @@ static int imx319_probe(struct i2c_client *client) /* Initialize subdev */ v4l2_i2c_subdev_init(&imx319->sd, client, &imx319_subdev_ops); - /* Check module identity */ - ret = imx319_identify_module(imx319); - if (ret) { - dev_err(&client->dev, "failed to find sensor: %d", ret); - goto error_probe; + full_power = acpi_dev_state_d0(&client->dev); + if (full_power) { + /* Check module identity */ + ret = imx319_identify_module(imx319); + if (ret) { + dev_err(&client->dev, "failed to find sensor: %d", ret); + goto error_probe; + } } imx319->hwcfg = imx319_get_hwcfg(&client->dev); @@ -2488,11 +2503,9 @@ static int imx319_probe(struct i2c_client *client) if (ret < 0) goto error_media_entity; - /* - * Device is already turned on by i2c-core with ACPI domain PM. - * Enable runtime PM and turn off the device. - */ - pm_runtime_set_active(&client->dev); + /* Set the device's state to active if it's in D0 state. */ + if (full_power) + pm_runtime_set_active(&client->dev); pm_runtime_enable(&client->dev); pm_runtime_idle(&client->dev); @@ -2545,6 +2558,7 @@ static struct i2c_driver imx319_i2c_driver = { }, .probe_new = imx319_probe, .remove = imx319_remove, + .flags = I2C_DRV_ACPI_WAIVE_D0_PROBE, }; module_i2c_driver(imx319_i2c_driver); From 1e96078e0ae456cda0e02afd42b9a2b3734f45ba Mon Sep 17 00:00:00 2001 From: Sakari Ailus Date: Mon, 18 Oct 2021 15:17:29 +0300 Subject: [PATCH 6/7] at24: Support probing while in non-zero ACPI D state In certain use cases (where the chip is part of a camera module, and the camera module is wired together with a camera privacy LED), powering on the device during probe is undesirable. Add support for the at24 to execute probe while being in ACPI D state other than 0 (which means fully powered on). Signed-off-by: Sakari Ailus Reviewed-by: Tomasz Figa Acked-by: Bartosz Golaszewski Signed-off-by: Rafael J. Wysocki --- drivers/misc/eeprom/at24.c | 45 +++++++++++++++++++++++--------------- 1 file changed, 27 insertions(+), 18 deletions(-) diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c index 305ffad131a29..49ab656e8a96e 100644 --- a/drivers/misc/eeprom/at24.c +++ b/drivers/misc/eeprom/at24.c @@ -595,6 +595,7 @@ static int at24_probe(struct i2c_client *client) bool i2c_fn_i2c, i2c_fn_block; unsigned int i, num_addresses; struct at24_data *at24; + bool full_power; struct regmap *regmap; bool writable; u8 test_byte; @@ -747,14 +748,16 @@ static int at24_probe(struct i2c_client *client) i2c_set_clientdata(client, at24); - err = regulator_enable(at24->vcc_reg); - if (err) { - dev_err(dev, "Failed to enable vcc regulator\n"); - return err; - } + full_power = acpi_dev_state_d0(&client->dev); + if (full_power) { + err = regulator_enable(at24->vcc_reg); + if (err) { + dev_err(dev, "Failed to enable vcc regulator\n"); + return err; + } - /* enable runtime pm */ - pm_runtime_set_active(dev); + pm_runtime_set_active(dev); + } pm_runtime_enable(dev); at24->nvmem = devm_nvmem_register(dev, &nvmem_config); @@ -766,15 +769,18 @@ static int at24_probe(struct i2c_client *client) } /* - * Perform a one-byte test read to verify that the - * chip is functional. + * Perform a one-byte test read to verify that the chip is functional, + * unless powering on the device is to be avoided during probe (i.e. + * it's powered off right now). */ - err = at24_read(at24, 0, &test_byte, 1); - if (err) { - pm_runtime_disable(dev); - if (!pm_runtime_status_suspended(dev)) - regulator_disable(at24->vcc_reg); - return -ENODEV; + if (full_power) { + err = at24_read(at24, 0, &test_byte, 1); + if (err) { + pm_runtime_disable(dev); + if (!pm_runtime_status_suspended(dev)) + regulator_disable(at24->vcc_reg); + return -ENODEV; + } } pm_runtime_idle(dev); @@ -794,9 +800,11 @@ static int at24_remove(struct i2c_client *client) struct at24_data *at24 = i2c_get_clientdata(client); pm_runtime_disable(&client->dev); - if (!pm_runtime_status_suspended(&client->dev)) - regulator_disable(at24->vcc_reg); - pm_runtime_set_suspended(&client->dev); + if (acpi_dev_state_d0(&client->dev)) { + if (!pm_runtime_status_suspended(&client->dev)) + regulator_disable(at24->vcc_reg); + pm_runtime_set_suspended(&client->dev); + } return 0; } @@ -833,6 +841,7 @@ static struct i2c_driver at24_driver = { .probe_new = at24_probe, .remove = at24_remove, .id_table = at24_ids, + .flags = I2C_DRV_ACPI_WAIVE_D0_PROBE, }; static int __init at24_init(void) From dff5acfd87e17ce8be3566b9948dc5ad558b0425 Mon Sep 17 00:00:00 2001 From: Sakari Ailus Date: Wed, 10 Nov 2021 14:10:14 +0200 Subject: [PATCH 7/7] Documentation: ACPI: Fix non-D0 probe _DSC object example The original patch adding the example used _DSC Name when Method was intended. Fix this. Also replace spaces used for indentation with tabs in the example. Fixes: ed66f12ba4b1 ("Documentation: ACPI: Document _DSC object usage for enum power state") Reported-by: Bingbu Cao Signed-off-by: Sakari Ailus Signed-off-by: Rafael J. Wysocki --- Documentation/firmware-guide/acpi/non-d0-probe.rst | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/Documentation/firmware-guide/acpi/non-d0-probe.rst b/Documentation/firmware-guide/acpi/non-d0-probe.rst index 78781e1ab6a3d..7afd16701a02e 100644 --- a/Documentation/firmware-guide/acpi/non-d0-probe.rst +++ b/Documentation/firmware-guide/acpi/non-d0-probe.rst @@ -62,7 +62,7 @@ objects not relevant from the example point of view have been omitted. .. code-block:: text Device (CAM0) - { + { Name (_HID, "SONY319A") Name (_UID, Zero) Name (_CRS, ResourceTemplate () @@ -71,8 +71,8 @@ objects not relevant from the example point of view have been omitted. AddressingMode7Bit, "\\_SB.PCI0.I2C0", 0x00, ResourceConsumer) }) - Name (_DSC, 0, NotSerialized) + Method (_DSC, 0, NotSerialized) { Return (0x4) - } + } }