[PATCH 5.13 211/800] ACPI: scan: Rearrange dep_unmet initialization

From: Greg Kroah-Hartman
Date: Mon Jul 12 2021 - 04:24:44 EST


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

[ Upstream commit 6d27975851b134be8d2a170437210c9719e524aa ]

The dep_unmet field in struct acpi_device is used to store the
number of unresolved _DEP dependencies (that is, operation region
dependencies for which there are no drivers present) for the ACPI
device object represented by it.

That field is initialized to 1 for all ACPI device objects in
acpi_add_single_object(), via acpi_init_device_object(), so as to
avoid evaluating _STA prematurely for battery device objects in
acpi_scan_init_status(), and it is "fixed up" in acpi_bus_check_add()
after the acpi_add_single_object() called by it has returned.

This is not particularly straightforward and causes dep_unmet to
remain 1 for device objects without dependencies created by invoking
acpi_add_single_object() directly, outside acpi_bus_check_add().

For this reason, rearrange acpi_add_single_object() to initialize
dep_unmet completely before calling acpi_scan_init_status(), which
requires passing one extra bool argument to it, and update all of
its callers accordingly.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Reviewed-by: Hans de Goede <hdegoede@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/acpi/scan.c | 60 +++++++++++++++++++++------------------------
1 file changed, 28 insertions(+), 32 deletions(-)

diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index e10d38ac7cf2..438df8da6d12 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -1671,8 +1671,20 @@ void acpi_init_device_object(struct acpi_device *device, acpi_handle handle,
device_initialize(&device->dev);
dev_set_uevent_suppress(&device->dev, true);
acpi_init_coherency(device);
- /* Assume there are unmet deps to start with. */
- device->dep_unmet = 1;
+}
+
+static void acpi_scan_dep_init(struct acpi_device *adev)
+{
+ struct acpi_dep_data *dep;
+
+ mutex_lock(&acpi_dep_list_lock);
+
+ list_for_each_entry(dep, &acpi_dep_list, node) {
+ if (dep->consumer == adev->handle)
+ adev->dep_unmet++;
+ }
+
+ mutex_unlock(&acpi_dep_list_lock);
}

void acpi_device_add_finalize(struct acpi_device *device)
@@ -1688,7 +1700,7 @@ static void acpi_scan_init_status(struct acpi_device *adev)
}

static int acpi_add_single_object(struct acpi_device **child,
- acpi_handle handle, int type)
+ acpi_handle handle, int type, bool dep_init)
{
struct acpi_device *device;
int result;
@@ -1703,8 +1715,12 @@ static int acpi_add_single_object(struct acpi_device **child,
* acpi_bus_get_status() and use its quirk handling. Note that
* this must be done before the get power-/wakeup_dev-flags calls.
*/
- if (type == ACPI_BUS_TYPE_DEVICE || type == ACPI_BUS_TYPE_PROCESSOR)
+ if (type == ACPI_BUS_TYPE_DEVICE || type == ACPI_BUS_TYPE_PROCESSOR) {
+ if (dep_init)
+ acpi_scan_dep_init(device);
+
acpi_scan_init_status(device);
+ }

acpi_bus_get_power_flags(device);
acpi_bus_get_wakeup_device_flags(device);
@@ -1886,22 +1902,6 @@ static u32 acpi_scan_check_dep(acpi_handle handle, bool check_dep)
return count;
}

-static void acpi_scan_dep_init(struct acpi_device *adev)
-{
- struct acpi_dep_data *dep;
-
- adev->dep_unmet = 0;
-
- mutex_lock(&acpi_dep_list_lock);
-
- list_for_each_entry(dep, &acpi_dep_list, node) {
- if (dep->consumer == adev->handle)
- adev->dep_unmet++;
- }
-
- mutex_unlock(&acpi_dep_list_lock);
-}
-
static bool acpi_bus_scan_second_pass;

static acpi_status acpi_bus_check_add(acpi_handle handle, bool check_dep,
@@ -1949,19 +1949,15 @@ static acpi_status acpi_bus_check_add(acpi_handle handle, bool check_dep,
return AE_OK;
}

- acpi_add_single_object(&device, handle, type);
- if (!device)
- return AE_CTRL_DEPTH;
-
- acpi_scan_init_hotplug(device);
/*
* If check_dep is true at this point, the device has no dependencies,
* or the creation of the device object would have been postponed above.
*/
- if (check_dep)
- device->dep_unmet = 0;
- else
- acpi_scan_dep_init(device);
+ acpi_add_single_object(&device, handle, type, !check_dep);
+ if (!device)
+ return AE_CTRL_DEPTH;
+
+ acpi_scan_init_hotplug(device);

out:
if (!*adev_p)
@@ -2223,7 +2219,7 @@ int acpi_bus_register_early_device(int type)
struct acpi_device *device = NULL;
int result;

- result = acpi_add_single_object(&device, NULL, type);
+ result = acpi_add_single_object(&device, NULL, type, false);
if (result)
return result;

@@ -2243,7 +2239,7 @@ static int acpi_bus_scan_fixed(void)
struct acpi_device *device = NULL;

result = acpi_add_single_object(&device, NULL,
- ACPI_BUS_TYPE_POWER_BUTTON);
+ ACPI_BUS_TYPE_POWER_BUTTON, false);
if (result)
return result;

@@ -2259,7 +2255,7 @@ static int acpi_bus_scan_fixed(void)
struct acpi_device *device = NULL;

result = acpi_add_single_object(&device, NULL,
- ACPI_BUS_TYPE_SLEEP_BUTTON);
+ ACPI_BUS_TYPE_SLEEP_BUTTON, false);
if (result)
return result;

--
2.30.2