Merge tag 'acpi-5.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull ACPI updates from Rafael Wysocki:
 "These rework the handling of ACPI device objects to use the driver
  core facilities for managing child ones instead of some questionable
  home-grown ways without the requisite locking and reference counting,
  clean up the EC driver, improve suspend-to-idle handling on x86, add
  some systems to the ACPI backlight quirk list, fix some assorted
  issues, clean up code and improve documentation.

  Specifics:

   - Use facilities provided by the driver core and some additional
     helpers to handle the children of a given ACPI device object in
     multiple places instead of using the children and node list heads
     in struct acpi_device which is error prone (Rafael Wysocki).

   - Fix ACPI-related device reference counting issue in the hisi_lpc
     bus driver (Yang Yingliang).

   - Drop the children and node list heads that are not needed any more
     from struct acpi_device (Rafael Wysocki).

   - Drop driver member from struct acpi_device (Uwe Kleine-König).

   - Drop redundant check from acpi_device_remove() (Uwe Kleine-König).

   - Prepare the CPPC library for handling backwards-compatible future
     _CPC return package formats gracefully (Rafael Wysocki).

   - Clean up the ACPI EC driver after previous changes in it (Hans de
     Goede).

   - Drop leftover acpi_processor_get_limit_info() declaration (Riwen
     Lu).

   - Split out thermal initialization from ACPI PSS (Riwen Lu).

   - Annotate more functions in the ACPI CPU idle driver to live in the
     cpuidle section (Guilherme G. Piccoli).

   - Fix _EINJ vs "special purpose" EFI memory regions (Dan Williams).

   - Implement a better fix to avoid spamming the console with old error
     logs (Tony Luck).

   - Fix typo in a comment in the APEI code (Xiang wangx).

   - Save NVS memory during transitions into S3 on Lenovo G40-45 (Manyi
     Li).

   - Add support for upcoming AMD uPEP device ID AMDI008 to the ACPI
     suspend-to-idle driver for x86 platforms (Shyam Sundar S K).

   - Clean up checks related to the ACPI_FADT_LOW_POWER_S0 platform flag
     in the LPIT table driver and the suspend-to-idle driver for x86
     platforms (Rafael Wysocki).

   - Print information messages regarding declared LPS0 idle support in
     the platform firmware (Rafael Wysocki).

   - Fix missing check in register_device_clock() in the ACPI driver for
     Intel SoCs (huhai).

   - Fix ACS setup in the VIOT table parser (Eric Auger).

   - Skip IRQ override on AMD Zen platforms where it's harmful
     (Chuanhong Guo).

   - Use native backlight on Dell Inspiron N4010 (Hans de Goede).

   - Use native backlight on some TongFang devices (Werner Sembach).

   - Drop X86 dependency from the ACPI backlight driver Kconfig (Riwen
     Lu).

   - Shorten the quirk list in the ACPI backlight driver by identifying
     Clevo by board_name only (Werner Sembach).

   - Remove useless NULL pointer checks from 2 ACPI PCI link management
     functions (Andrey Strachuk).

   - Fix obsolete example in the ACPI EINJ documentation (Qifu Zhang).

   - Update links and references to _DSD-related documents (Sudeep
     Holla)"

* tag 'acpi-5.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (46 commits)
  ACPI/PCI: Remove useless NULL pointer checks
  ACPI: CPPC: Do not prevent CPPC from working in the future
  ACPI: PM: x86: Print messages regarding LPS0 idle support
  ACPI: resource: skip IRQ override on AMD Zen platforms
  Documentation: ACPI: EINJ: Fix obsolete example
  ACPI: video: Use native backlight on Dell Inspiron N4010
  ACPI: PM: s2idle: Use LPS0 idle if ACPI_FADT_LOW_POWER_S0 is unset
  Revert "ACPI / PM: LPIT: Register sysfs attributes based on FADT"
  ACPI: video: Shortening quirk list by identifying Clevo by board_name only
  ACPI: video: Force backlight native for some TongFang devices
  ACPI: PM: s2idle: Add support for upcoming AMD uPEP HID AMDI008
  ACPI: VIOT: Fix ACS setup
  ACPI: bus: Drop unused list heads from struct acpi_device
  hisi_lpc: Use acpi_dev_for_each_child()
  bus: hisi_lpc: fix missing platform_device_put() in hisi_lpc_acpi_probe()
  ACPI: bus: Drop driver member of struct acpi_device
  ACPI: bus: Drop redundant check in acpi_device_remove()
  ACPI: APEI: Fix _EINJ vs EFI_MEMORY_SP
  ACPI: LPSS: Fix missing check in register_device_clock()
  ACPI: APEI: Better fix to avoid spamming the console with old error logs
  ...

1 files changed, 24 insertions, 7 deletions

diff --git a/drivers/mfd/mfd-core.c b/drivers/mfd/mfd-core.c
index 684a011a6396..8b058200d5ad 100644
--- a/drivers/mfd/mfd-core.c
+++ b/drivers/mfd/mfd-core.c
@@ -60,12 +60,29 @@ int mfd_cell_disable(struct platform_device *pdev)
 EXPORT_SYMBOL(mfd_cell_disable);
 
 #if IS_ENABLED(CONFIG_ACPI)
+struct match_ids_walk_data {
+	struct acpi_device_id *ids;
+	struct acpi_device *adev;
+};
+
+static int match_device_ids(struct acpi_device *adev, void *data)
+{
+	struct match_ids_walk_data *wd = data;
+
+	if (!acpi_match_device_ids(adev, wd->ids)) {
+		wd->adev = adev;
+		return 1;
+	}
+
+	return 0;
+}
+
 static void mfd_acpi_add_device(const struct mfd_cell *cell,
 				struct platform_device *pdev)
 {
 	const struct mfd_cell_acpi_match *match = cell->acpi_match;
-	struct acpi_device *parent, *child;
 	struct acpi_device *adev = NULL;
+	struct acpi_device *parent;
 
 	parent = ACPI_COMPANION(pdev->dev.parent);
 	if (!parent)
@@ -83,14 +100,14 @@ static void mfd_acpi_add_device(const struct mfd_cell *cell,
 	if (match) {
 		if (match->pnpid) {
 			struct acpi_device_id ids[2] = {};
+			struct match_ids_walk_data wd = {
+				.adev = NULL,
+				.ids = ids,
+			};
 
 			strlcpy(ids[0].id, match->pnpid, sizeof(ids[0].id));
-			list_for_each_entry(child, &parent->children, node) {
-				if (!acpi_match_device_ids(child, ids)) {
-					adev = child;
-					break;
-				}
-			}
+			acpi_dev_for_each_child(parent, match_device_ids, &wd);
+			adev = wd.adev;
 		} else {
 			adev = acpi_find_child_device(parent, match->adr, false);
 		}