From bc28368596436e6e81ffc48c815b8225d96121c0 Mon Sep 17 00:00:00 2001
From: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Date: Fri, 15 Oct 2021 19:12:21 +0200
Subject: [PATCH] ACPI: PM: Do not turn off power resources in unknown state
Commit 6381195ad7d0 ("ACPI: power: Rework turning off unused power
resources") caused power resources in unknown state with reference
counters equal to zero to be turned off too, but that caused issues
to appear in the field, so modify the code to only turn off power
resources that are known to be "on".
Link: https://lore.kernel.org/linux-acpi/6faf4b92-78d5-47a4-63df-cc2bab7769d0@molgen.mpg.de/
Fixes: 6381195ad7d0 ("ACPI: power: Rework turning off unused power resources")
Reported-by: Andreas K. Huettel <andreas.huettel@ur.de>
Tested-by: Andreas K. Huettel <andreas.huettel@ur.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: 5.14+ <stable@vger.kernel.org> # 5.14+
---
drivers/acpi/power.c | 7 +------
1 file changed, 1 insertion(+), 6 deletions(-)
diff --git a/drivers/acpi/power.c b/drivers/acpi/power.c
index b9863e22b952d..f0ed4414edb1f 100644
--- a/drivers/acpi/power.c
+++ b/drivers/acpi/power.c
@@ -1035,13 +1035,8 @@ void acpi_turn_off_unused_power_resources(void)
list_for_each_entry_reverse(resource, &acpi_power_resource_list, list_node) {
mutex_lock(&resource->resource_lock);
- /*
- * Turn off power resources in an unknown state too, because the
- * platform firmware on some system expects the OS to turn off
- * power resources without any users unconditionally.
- */
if (!resource->ref_count &&
- resource->state != ACPI_POWER_RESOURCE_STATE_OFF) {
+ resource->state == ACPI_POWER_RESOURCE_STATE_ON) {
acpi_handle_debug(resource->device.handle, "Turning OFF\n");
__acpi_power_off(resource);
}
--
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