linux-kernel - [PATCH v3 8/9] ACPI: PM: Set/clear power.strict

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Message-ID: <4463062.ejJDZkT8p0@rjwysocki.net>
Date: Fri, 27 Jun 2025 21:25:22 +0200
From: "Rafael J. Wysocki" <rjw@...ysocki.net>
To: Linux PM <linux-pm@...r.kernel.org>
Cc: LKML <linux-kernel@...r.kernel.org>,
 Linux ACPI <linux-acpi@...r.kernel.org>,
 Linux PCI <linux-pci@...r.kernel.org>, Ulf Hansson <ulf.hansson@...aro.org>,
 Mika Westerberg <mika.westerberg@...ux.intel.com>
Subject:
 [PATCH v3 8/9] ACPI: PM: Set/clear power.strict_midlayer in prepare/complete

From: Rafael J. Wysocki <rafael.j.wysocki@...el.com>

The ACPI general PM domain and the LPSS PM domain do not expect their
mid-layer runtime PM suspend callbacks to be invoked at all during
system-wide suspend and resume and they do not expect their runtime
resume callbacks to be invoked at any point when runtime PM is disabled
for the given device during system suspend and resume, so make
acpi_subsys_prepare() set power.strict_midlayer for the given device
to express that expectation and make acpi_subsys_complete() clear it.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
---

v2 -> v3: Update the changelog to be more precise.

v1 -> v2:
   * Set and clear the new flag in "prepare" and "complete" instead of
     "attach" and "detach", respectively, to (1) cover the LPSS PM domain as
     well as the general ACPI PM domain and (2) allow pm_runtime_force_suspend()
     invoked from driver remove callbacks to work.
   * Update subject and changelog.

---
 drivers/acpi/device_pm.c |    4 ++++
 1 file changed, 4 insertions(+)

--- a/drivers/acpi/device_pm.c
+++ b/drivers/acpi/device_pm.c
@@ -1119,6 +1119,8 @@
 {
 	struct acpi_device *adev = ACPI_COMPANION(dev);

+	dev_pm_set_strict_midlayer(dev, true);
+
 	if (dev->driver && dev->driver->pm && dev->driver->pm->prepare) {
 		int ret = dev->driver->pm->prepare(dev);

@@ -1147,6 +1149,8 @@
 	 */
 	if (pm_runtime_suspended(dev) && pm_resume_via_firmware())
 		pm_request_resume(dev);
+
+	dev_pm_set_strict_midlayer(dev, false);
 }
 EXPORT_SYMBOL_GPL(acpi_subsys_complete);