[PATCH v1] ACPI: glue: Rearrange find_child_checks()

From: Rafael J. Wysocki
Date: Thu May 05 2022 - 14:53:58 EST


From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>

Notice that it is not necessary to evaluate _STA in find_child_checks()
if the device is expected to have children, but there are none, so
move the children check to the front of the function.

Also notice that FIND_CHILD_MIN_SCORE can be returned right away if
_STA is missing, so make the function do so.

Finally, replace the ternary operator in the return statement argument
with an if () and a standalone return which is somewhat easier to
follow.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
---
drivers/acpi/glue.c | 16 +++++++++-------
1 file changed, 9 insertions(+), 7 deletions(-)

Index: linux-pm/drivers/acpi/glue.c
===================================================================
--- linux-pm.orig/drivers/acpi/glue.c
+++ linux-pm/drivers/acpi/glue.c
@@ -79,17 +79,17 @@ static struct acpi_bus_type *acpi_get_bu

static int find_child_checks(struct acpi_device *adev, bool check_children)
{
- bool sta_present = true;
unsigned long long sta;
acpi_status status;

+ if (check_children && list_empty(&adev->children))
+ return -ENODEV;
+
status = acpi_evaluate_integer(adev->handle, "_STA", NULL, &sta);
if (status == AE_NOT_FOUND)
- sta_present = false;
- else if (ACPI_FAILURE(status) || !(sta & ACPI_STA_DEVICE_ENABLED))
- return -ENODEV;
+ return FIND_CHILD_MIN_SCORE;

- if (check_children && list_empty(&adev->children))
+ if (ACPI_FAILURE(status) || !(sta & ACPI_STA_DEVICE_ENABLED))
return -ENODEV;

/*
@@ -99,8 +99,10 @@ static int find_child_checks(struct acpi
* matched going forward. [This means a second spec violation in a row,
* so whatever we do here is best effort anyway.]
*/
- return sta_present && !adev->pnp.type.platform_id ?
- FIND_CHILD_MAX_SCORE : FIND_CHILD_MIN_SCORE;
+ if (adev->pnp.type.platform_id)
+ return FIND_CHILD_MIN_SCORE;
+
+ return FIND_CHILD_MAX_SCORE;
}

struct acpi_device *acpi_find_child_device(struct acpi_device *parent,