ACPI: scan: Do not increase dep_unmet for already met dependencies

On the Toshiba Encore WT10-A tablet the BATC battery ACPI device depends
on 3 other devices:

            Name (_DEP, Package (0x03)  // _DEP: Dependencies
            {
                I2C1,
                GPO2,
                GPO0
            })

acpi_scan_check_dep() adds all 3 of these to the acpi_dep_list and then
before an acpi_device is created for the BATC handle (and thus before
acpi_scan_dep_init() runs) acpi_scan_clear_dep() gets called for both
GPIO depenencies, with free_when_met not set for the dependencies.

Since there is no adev for BATC yet, there also is no dep_unmet to
decrement. The only result of acpi_scan_clear_dep() in this case is
dep->met getting set.

Soon after acpi_scan_clear_dep() has been called for the GPIO dependencies
the acpi_device gets created for the BATC handle and acpi_scan_dep_init()
runs, this sees 3 dependencies on the acpi_dep_list and initializes
unmet_dep to 3. Later when the dependency for I2C1 is met unmet_dep
becomes 2, but since the 2 GPIO deps where already met it never becomes 0
causing battery monitoring to not work.

Fix this by modifying acpi_scan_dep_init() to not increase dep_met for
dependencies which have already been marked as being met.

Fixes: 3ba12d8de3fa ("ACPI: scan: Reduce overhead related to devices with dependencies")
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Cc: 6.5+ <stable@vger.kernel.org> # 6.5+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 7c157bf92695..d1464324de95 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -1843,7 +1843,8 @@ static void acpi_scan_dep_init(struct acpi_device *adev)
 			if (dep->honor_dep)
 				adev->flags.honor_deps = 1;
 
-			adev->dep_unmet++;
+			if (!dep->met)
+				adev->dep_unmet++;
 		}
 	}
 }