Commit 285fc3db authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'acpi-5.16-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm 

Pull more ACPI updates from Rafael Wysocki:
 "These add support for a new ACPI device configuration object called
  _DSC, fix some issues including one recent regression, add two new
  items to quirk lists and clean up assorted pieces of code.

  Specifics:

   - Add support for new ACPI device configuration object called _DSC
     ("Deepest State for Configuration") to allow certain devices to be
     probed without changing their power states, document it and make
     two drivers use it (Sakari Ailus, Rajmohan Mani).

   - Fix device wakeup power reference counting broken recently by
     mistake (Rafael Wysocki).

   - Drop unused symbol and macros depending on it from acgcc.h (Rafael
     Wysocki).

   - Add HP ZHAN 66 Pro to the "no EC wakeup" quirk list (Binbin Zhou).

   - Add Xiaomi Mi Pad 2 to the backlight quirk list and drop an unused
     piece of data from all of the list entries (Hans de Goede).

   - Fix register read accesses handling in the Intel PMIC operation
     region driver (Hans de Goede).

   - Clean up static variables initialization in the EC driver
     (wangzhitong)"

* tag 'acpi-5.16-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  Documentation: ACPI: Fix non-D0 probe _DSC object example
  ACPI: Drop ACPI_USE_BUILTIN_STDARG ifdef from acgcc.h
  ACPI: PM: Fix device wakeup power reference counting error
  ACPI: video: use platform backlight driver on Xiaomi Mi Pad 2
  ACPI: video: Drop dmi_system_id.ident settings from video_detect_dmi_table[]
  ACPI: PMIC: Fix intel_pmic_regs_handler() read accesses
  ACPI: EC: Remove initialization of static variables to false
  ACPI: EC: Use ec_no_wakeup on HP ZHAN 66 Pro
  at24: Support probing while in non-zero ACPI D state
  media: i2c: imx319: Support device probe in non-zero ACPI D state
  ACPI: Add a convenience function to tell a device is in D0 state
  Documentation: ACPI: Document _DSC object usage for enum power state
  i2c: Allow an ACPI driver to manage the device's power state during probe
  ACPI: scan: Obtain device's desired enumeration power state
parents e68a7d35 314c6e2b

Documentation/firmware-guide/acpi/index.rst

+1 −0
Original line number Diff line number Diff line
@@ -26,5 +26,6 @@ ACPI Support 
   acpi-lid

   lpit

   video_extension

   non-d0-probe

   extcon-intel-int3496

   intel-pmc-mux

Documentation/firmware-guide/acpi/non-d0-probe.rst

0 → 100644
+78 −0
Original line number Diff line number Diff line 
.. 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)

		})

		Method (_DSC, 0, NotSerialized)

		{

			Return (0x4)

		}

	}

drivers/acpi/device_pm.c

+26 −0
Original line number Diff line number Diff line
@@ -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 */

drivers/acpi/ec.c

+9 −2
Original line number Diff line number Diff line
@@ -133,7 +133,7 @@ static unsigned int ec_storm_threshold __read_mostly = 8; 
module_param(ec_storm_threshold, uint, 0644);

MODULE_PARM_DESC(ec_storm_threshold, "Maxim false GPE numbers not considered as GPE storm");



static bool ec_freeze_events __read_mostly = false;

static bool ec_freeze_events __read_mostly;

module_param(ec_freeze_events, bool, 0644);

MODULE_PARM_DESC(ec_freeze_events, "Disabling event handling during suspend/resume");
@@ -177,7 +177,7 @@ struct acpi_ec *first_ec; 
EXPORT_SYMBOL(first_ec);



static struct acpi_ec *boot_ec;

static bool boot_ec_is_ecdt = false;

static bool boot_ec_is_ecdt;

static struct workqueue_struct *ec_wq;

static struct workqueue_struct *ec_query_wq;
@@ -2152,6 +2152,13 @@ static const struct dmi_system_id acpi_ec_no_wakeup[] = { 
			DMI_MATCH(DMI_PRODUCT_FAMILY, "ThinkPad X1 Yoga 3rd"),

		},

	},

	{

		.ident = "HP ZHAN 66 Pro",

		.matches = {

			DMI_MATCH(DMI_SYS_VENDOR, "HP"),

			DMI_MATCH(DMI_PRODUCT_FAMILY, "103C_5336AN HP ZHAN 66 Pro"),

		},

	},

	{ },

};

drivers/acpi/pmic/intel_pmic.c

+28 −23
Original line number Diff line number Diff line
@@ -211,8 +211,9 @@ static acpi_status intel_pmic_regs_handler(u32 function, 
		void *handler_context, void *region_context)

{

	struct intel_pmic_opregion *opregion = region_context;

	int result = 0;

	int result = -EINVAL;



	if (function == ACPI_WRITE) {

		switch (address) {

		case 0:

			return AE_OK;
@@ -232,10 +233,14 @@ static acpi_status intel_pmic_regs_handler(u32 function, 
			} else {

				result = regmap_read(opregion->regmap, opregion->ctx.addr,

						     &opregion->ctx.val);

			if (result == 0)

				*value64 = opregion->ctx.val;

			}

		memset(&opregion->ctx, 0x00, sizeof(opregion->ctx));

			opregion->ctx.addr = 0;

		}

	}



	if (function == ACPI_READ && address == 3) {

		*value64 = opregion->ctx.val;

		return AE_OK;

	}



	if (result < 0) {