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

Message ID 20240406114052.4884-1-hdegoede@redhat.com (mailing list archive)
State Mainlined, archived
Headers show
Series ACPI: scan: Do not increase dep_unmet for already met dependencies | expand

Commit Message

Hans de Goede April 6, 2024, 11:40 a.m. UTC
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>
---
 drivers/acpi/scan.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Comments

Rafael J. Wysocki April 8, 2024, 2:48 p.m. UTC | #1
On Sat, Apr 6, 2024 at 1:43 PM Hans de Goede <hdegoede@redhat.com> wrote:
>
> 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>
> ---
>  drivers/acpi/scan.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> 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++;

Nice catch!

>                 }
>         }
>  }
> --

Applied as 6.9-rc material, thanks!
diff mbox series

Patch

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++;
 		}
 	}
 }