[PATCH v1 0/3] ACPI: scan: acpi_scan_init() updates

[PATCH v1 0/3] ACPI: scan: acpi_scan_init() updates

[Rafael J. Wysocki]

Hi All,

There are some minor defects in acpi_scan_init() and because recent changes
cause static checkers to catch them, it is better to address them right away.

Please see patch changelogs for the details.

Thanks!

[PATCH v1 1/3] ACPI: scan: Change acpi_scan_init() return value type to void

[Rafael J. Wysocki]

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

The only caller of acpi_scan_init(), acpi_init(), doesn't check its
return value, so turn it into a void function.

This avoids complaints from the Smatch static checker that the
function should return a negative error code when it fails, which
is not really a problem in this particular case.

No intentional functional impact.

Link: https://lore.kernel.org/linux-acpi/20220106082317.GA9123@kili/
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
 drivers/acpi/internal.h |    2 +-
 drivers/acpi/scan.c     |   10 +++-------
 2 files changed, 4 insertions(+), 8 deletions(-)

Index: linux-pm/drivers/acpi/scan.c
===================================================================
--- linux-pm.orig/drivers/acpi/scan.c
+++ linux-pm/drivers/acpi/scan.c
@@ -2513,9 +2513,8 @@ static void __init acpi_get_spcr_uart_ad
 
 static bool acpi_scan_initialized;
 
-int __init acpi_scan_init(void)
+void __init acpi_scan_init(void)
 {
-	int result;
 	acpi_status status;
 	struct acpi_table_stao *stao_ptr;
 
@@ -2565,8 +2564,7 @@ int __init acpi_scan_init(void)
 	/*
 	 * Enumerate devices in the ACPI namespace.
 	 */
-	result = acpi_bus_scan(ACPI_ROOT_OBJECT);
-	if (result)
+	if (acpi_bus_scan(ACPI_ROOT_OBJECT))
 		goto out;
 
 	acpi_root = acpi_fetch_acpi_dev(ACPI_ROOT_OBJECT);
@@ -2575,8 +2573,7 @@ int __init acpi_scan_init(void)
 
 	/* Fixed feature devices do not exist on HW-reduced platform */
 	if (!acpi_gbl_reduced_hardware) {
-		result = acpi_bus_scan_fixed();
-		if (result) {
+		if (acpi_bus_scan_fixed()) {
 			acpi_detach_data(acpi_root->handle,
 					 acpi_scan_drop_device);
 			acpi_device_del(acpi_root);
@@ -2591,7 +2588,6 @@ int __init acpi_scan_init(void)
 
  out:
 	mutex_unlock(&acpi_scan_lock);
-	return result;
 }
 
 static struct acpi_probe_entry *ape;
Index: linux-pm/drivers/acpi/internal.h
===================================================================
--- linux-pm.orig/drivers/acpi/internal.h
+++ linux-pm/drivers/acpi/internal.h
@@ -14,7 +14,7 @@
 int early_acpi_osi_init(void);
 int acpi_osi_init(void);
 acpi_status acpi_os_initialize1(void);
-int acpi_scan_init(void);
+void acpi_scan_init(void);
 #ifdef CONFIG_PCI
 void acpi_pci_root_init(void);
 void acpi_pci_link_init(void);

[PATCH v1 2/3] ACPI: scan: Simplify initialization of power and sleep buttons

[Rafael J. Wysocki]

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

It should be perfectly fine to use ACPI if the "fixed" power or sleep
buttons cannot be initialized.  Moreover, running acpi_bus_scan()
successfully on ACPI_ROOT_OBJECT generally causes many devices to
be enumerated and probed, possibly including the entire PCI bus, so
unregistering acpi_root if the registration of the "fixed" buttons
fails is rather unhelpful.

For this reason, do not fail acpi_scan_init() when
acpi_bus_scan_fixed() fails and turn the latter into a void function.

While at it, drop the outdated and misleading comment from
acpi_bus_scan_fixed().

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
 drivers/acpi/scan.c |   58 ++++++++++++++++++----------------------------------
 1 file changed, 21 insertions(+), 37 deletions(-)

Index: linux-pm/drivers/acpi/scan.c
===================================================================
--- linux-pm.orig/drivers/acpi/scan.c
+++ linux-pm/drivers/acpi/scan.c
@@ -2457,42 +2457,33 @@ int acpi_bus_register_early_device(int t
 }
 EXPORT_SYMBOL_GPL(acpi_bus_register_early_device);
 
-static int acpi_bus_scan_fixed(void)
+static void acpi_bus_scan_fixed(void)
 {
-	int result = 0;
-
-	/*
-	 * Enumerate all fixed-feature devices.
-	 */
 	if (!(acpi_gbl_FADT.flags & ACPI_FADT_POWER_BUTTON)) {
-		struct acpi_device *device = NULL;
+		struct acpi_device *adev = NULL;
 
-		result = acpi_add_single_object(&device, NULL,
-						ACPI_BUS_TYPE_POWER_BUTTON, false);
-		if (result)
-			return result;
-
-		device->flags.match_driver = true;
-		result = device_attach(&device->dev);
-		if (result < 0)
-			return result;
-
-		device_init_wakeup(&device->dev, true);
+		acpi_add_single_object(&adev, NULL, ACPI_BUS_TYPE_POWER_BUTTON,
+				       false);
+		if (adev) {
+			adev->flags.match_driver = true;
+			if (device_attach(&adev->dev) >= 0)
+				device_init_wakeup(&adev->dev, true);
+			else
+				dev_dbg(&adev->dev, "No driver\n");
+		}
 	}
 
 	if (!(acpi_gbl_FADT.flags & ACPI_FADT_SLEEP_BUTTON)) {
-		struct acpi_device *device = NULL;
+		struct acpi_device *adev = NULL;
 
-		result = acpi_add_single_object(&device, NULL,
-						ACPI_BUS_TYPE_SLEEP_BUTTON, false);
-		if (result)
-			return result;
-
-		device->flags.match_driver = true;
-		result = device_attach(&device->dev);
+		acpi_add_single_object(&adev, NULL, ACPI_BUS_TYPE_SLEEP_BUTTON,
+				       false);
+		if (adev) {
+			adev->flags.match_driver = true;
+			if (device_attach(&adev->dev) < 0)
+				dev_dbg(&adev->dev, "No driver\n");
+		}
 	}
-
-	return result < 0 ? result : 0;
 }
 
 static void __init acpi_get_spcr_uart_addr(void)
@@ -2572,15 +2563,8 @@ void __init acpi_scan_init(void)
 		goto out;
 
 	/* Fixed feature devices do not exist on HW-reduced platform */
-	if (!acpi_gbl_reduced_hardware) {
-		if (acpi_bus_scan_fixed()) {
-			acpi_detach_data(acpi_root->handle,
-					 acpi_scan_drop_device);
-			acpi_device_del(acpi_root);
-			acpi_bus_put_acpi_device(acpi_root);
-			goto out;
-		}
-	}
+	if (!acpi_gbl_reduced_hardware)
+		acpi_bus_scan_fixed();
 
 	acpi_turn_off_unused_power_resources();
 

[PATCH v1 3/3] ACPI: scan: Rename label in acpi_scan_init()

[Rafael J. Wysocki]

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

Rename the "out" label in acpi_scan_init() to "unlock", which is
a better match for its purpose, and fix up the alignment.

No functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
 drivers/acpi/scan.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

Index: linux-pm/drivers/acpi/scan.c
===================================================================
--- linux-pm.orig/drivers/acpi/scan.c
+++ linux-pm/drivers/acpi/scan.c
@@ -2556,11 +2556,11 @@ void __init acpi_scan_init(void)
 	 * Enumerate devices in the ACPI namespace.
 	 */
 	if (acpi_bus_scan(ACPI_ROOT_OBJECT))
-		goto out;
+		goto unlock;
 
 	acpi_root = acpi_fetch_acpi_dev(ACPI_ROOT_OBJECT);
 	if (!acpi_root)
-		goto out;
+		goto unlock;
 
 	/* Fixed feature devices do not exist on HW-reduced platform */
 	if (!acpi_gbl_reduced_hardware)
@@ -2570,7 +2570,7 @@ void __init acpi_scan_init(void)
 
 	acpi_scan_initialized = true;
 
- out:
+unlock:
 	mutex_unlock(&acpi_scan_lock);
 }
 

Re: [PATCH v1 0/3] ACPI: scan: acpi_scan_init() updates

[Mika Westerberg]

On Tue, Jan 11, 2022 at 05:45:23PM +0100, Rafael J. Wysocki wrote:
> Hi All,
> 
> There are some minor defects in acpi_scan_init() and because recent changes
> cause static checkers to catch them, it is better to address them right away.

Looks good to me :)

Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>

Re: [PATCH v1 0/3] ACPI: scan: acpi_scan_init() updates

[Hans de Goede]

Hi,

On 1/11/22 17:45, Rafael J. Wysocki wrote:
> Hi All,
> 
> There are some minor defects in acpi_scan_init() and because recent changes
> cause static checkers to catch them, it is better to address them right away.
> 
> Please see patch changelogs for the details.

The entire series looks good to me:

Reviewed-by: Hans de Goede <hdegoede@redhat.com>

for the series.

Regards,

Hans