linux-kernel - [PATCH 3.16 079/245] ACPI: PM: Avoid attaching ACPI PM domain to certain devices

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Date:   Fri, 24 Apr 2020 00:05:06 +0100
From:   Ben Hutchings <ben@...adent.org.uk>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
CC:     akpm@...ux-foundation.org, Denis Kirjanov <kda@...ux-powerpc.org>,
        "Todd Brandt" <todd.e.brandt@...ux.intel.com>,
        "Zhang Rui" <rui.zhang@...el.com>,
        "Rafael J. Wysocki" <rafael.j.wysocki@...el.com>
Subject: [PATCH 3.16 079/245] ACPI: PM: Avoid attaching ACPI PM domain to
 certain devices

3.16.83-rc1 review patch.  If anyone has any objections, please let me know.

------------------

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

commit b9ea0bae260f6aae546db224daa6ac1bd9d94b91 upstream.

Certain ACPI-enumerated devices represented as platform devices in
Linux, like fans, require special low-level power management handling
implemented by their drivers that is not in agreement with the ACPI
PM domain behavior.  That leads to problems with managing ACPI fans
during system-wide suspend and resume.

For this reason, make acpi_dev_pm_attach() skip the affected devices
by adding a list of device IDs to avoid to it and putting the IDs of
the affected devices into that list.

Fixes: e5cc8ef31267 (ACPI / PM: Provide ACPI PM callback routines for subsystems)
Reported-by: Zhang Rui <rui.zhang@...el.com>
Tested-by: Todd Brandt <todd.e.brandt@...ux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@...adent.org.uk>
---
 drivers/acpi/device_pm.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

--- a/drivers/acpi/device_pm.c
+++ b/drivers/acpi/device_pm.c
@@ -1041,9 +1041,19 @@ static struct dev_pm_domain acpi_general
  */
 int acpi_dev_pm_attach(struct device *dev, bool power_on)
 {
+	/*
+	 * Skip devices whose ACPI companions match the device IDs below,
+	 * because they require special power management handling incompatible
+	 * with the generic ACPI PM domain.
+	 */
+	static const struct acpi_device_id special_pm_ids[] = {
+		{"PNP0C0B", }, /* Generic ACPI fan */
+		{"INT3404", }, /* Fan */
+		{}
+	};
 	struct acpi_device *adev = ACPI_COMPANION(dev);
 
-	if (!adev)
+	if (!adev || !acpi_match_device_ids(adev, special_pm_ids))
 		return -ENODEV;
 
 	if (dev->pm_domain)