[PATCH 6.8 016/172] ACPI: scan: Do not increase dep_unmet for already met dependencies

Greg Kroah-Hartman
2024-04-15T14:26:06Z

From: Hans de Goede <hdegoede@redhat.com>

commit d730192ff0246356a2d7e63ff5bd501060670eec upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/acpi/scan.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -1802,7 +1802,8 @@ static void acpi_scan_dep_init(struct ac
if (dep->honor_dep)
adev->flags.honor_deps = 1;

- adev->dep_unmet++;
+ if (!dep->met)
+ adev->dep_unmet++;
}
}
}