[PATCH 0/2] ACPI: Device enumeration udates

[PATCH 0/2] ACPI: Device enumeration udates

[Rafael J. Wysocki]

Hi,

These two patches change a couple of things related to the ACPI enumeration of
devices.

[1/2] causes the default enumeration to also be used for device objects with
ACPI drivers bound for consistency.

[2/2] makes acpi_bus_attach() look at the "visited" flag of device objects as
it should really.

Please let me know if you see any potential problems with these patches.

Thanks,
Rafael

[PATCH 1/2] ACPI / scan: Apply default enumeration to devices with ACPI drivers

[Rafael J. Wysocki]

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

The current code in acpi_bus_attach() is inconsistent with respect
to device objects with ACPI drivers bound to them, as it allows
ACPI drivers to bind to device objects with existing "physical"
device companions, but it doesn't allow "physical" device objects
to be created for ACPI device objects with ACPI drivers bound to
them.  Thus, in some cases, the outcome depends on the ordering
of events which is confusing at best.

For this reason, modify acpi_bus_attach() to call
acpi_default_enumeration() for device objects with the 
pnp.type.platform_id flag set regardless of whether or not
any ACPI drivers are bound to them.

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
@@ -1866,10 +1866,10 @@ static void acpi_bus_attach(struct acpi_
 	if (ret < 0)
 		return;
 
-	if (ret > 0 || !device->pnp.type.platform_id)
-		acpi_device_set_enumerated(device);
-	else
+	if (device->pnp.type.platform_id)
 		acpi_default_enumeration(device);
+	else
+		acpi_device_set_enumerated(device);
 
  ok:
 	list_for_each_entry(child, &device->children, node)

[PATCH 2/2] ACPI / scan: Avoid enumerating devices more than once

[Rafael J. Wysocki]

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

acpi_bus_attach() does not check the visited flag for devices that
have been enumerated already and some of them may be enumerated
for multiple times as a result, because some callers of
acpi_bus_scan() don't check the visited flag either.

For this reason, modify acpi_bus_attach() to check the visited flag
and avoid enumerating devices that have already been enumerated.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
 drivers/acpi/scan.c |    2 ++
 1 file changed, 2 insertions(+)

Index: linux-pm/drivers/acpi/scan.c
===================================================================
--- linux-pm.orig/drivers/acpi/scan.c
+++ linux-pm/drivers/acpi/scan.c
@@ -1850,6 +1850,8 @@ static void acpi_bus_attach(struct acpi_
 			device->flags.power_manageable = 0;
 
 		device->flags.initialized = true;
+	} else if (device->flags.visited) {
+		goto ok;
 	}
 
 	ret = acpi_scan_attach_handler(device);

Re: [PATCH 1/2] ACPI / scan: Apply default enumeration to devices with ACPI drivers

[Mika Westerberg]

On Mon, Apr 17, 2017 at 01:19:50AM +0200, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> 
> The current code in acpi_bus_attach() is inconsistent with respect
> to device objects with ACPI drivers bound to them, as it allows
> ACPI drivers to bind to device objects with existing "physical"
> device companions, but it doesn't allow "physical" device objects
> to be created for ACPI device objects with ACPI drivers bound to
> them.  Thus, in some cases, the outcome depends on the ordering
> of events which is confusing at best.
> 
> For this reason, modify acpi_bus_attach() to call
> acpi_default_enumeration() for device objects with the 
> pnp.type.platform_id flag set regardless of whether or not
> any ACPI drivers are bound to them.
> 
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

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

Re: [PATCH 2/2] ACPI / scan: Avoid enumerating devices more than once

[Mika Westerberg]

On Mon, Apr 17, 2017 at 01:20:48AM +0200, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> 
> acpi_bus_attach() does not check the visited flag for devices that
> have been enumerated already and some of them may be enumerated
> for multiple times as a result, because some callers of
> acpi_bus_scan() don't check the visited flag either.
> 
> For this reason, modify acpi_bus_attach() to check the visited flag
> and avoid enumerating devices that have already been enumerated.
> 
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

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

Re: [PATCH 1/2] ACPI / scan: Apply default enumeration to devices with ACPI drivers

[joeyli]

On Mon, Apr 17, 2017 at 01:19:50AM +0200, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> 
> The current code in acpi_bus_attach() is inconsistent with respect
> to device objects with ACPI drivers bound to them, as it allows
> ACPI drivers to bind to device objects with existing "physical"
> device companions, but it doesn't allow "physical" device objects
> to be created for ACPI device objects with ACPI drivers bound to
> them.  Thus, in some cases, the outcome depends on the ordering
> of events which is confusing at best.
> 
> For this reason, modify acpi_bus_attach() to call
> acpi_default_enumeration() for device objects with the 
> pnp.type.platform_id flag set regardless of whether or not
> any ACPI drivers are bound to them.
> 
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

I did my best to review the context of codes in this patchset. 

Reviewed-by: Joey Lee <jlee@suse.com>

Thanka a lot!
Joey Lee

> ---
>  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
> @@ -1866,10 +1866,10 @@ static void acpi_bus_attach(struct acpi_
>  	if (ret < 0)
>  		return;
>  
> -	if (ret > 0 || !device->pnp.type.platform_id)
> -		acpi_device_set_enumerated(device);
> -	else
> +	if (device->pnp.type.platform_id)
>  		acpi_default_enumeration(device);
> +	else
> +		acpi_device_set_enumerated(device);
>  
>   ok:
>  	list_for_each_entry(child, &device->children, node)
> 

Re: [PATCH 2/2] ACPI / scan: Avoid enumerating devices more than once

[joeyli]

On Mon, Apr 17, 2017 at 01:20:48AM +0200, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> 
> acpi_bus_attach() does not check the visited flag for devices that
> have been enumerated already and some of them may be enumerated
> for multiple times as a result, because some callers of
> acpi_bus_scan() don't check the visited flag either.
> 
> For this reason, modify acpi_bus_attach() to check the visited flag
> and avoid enumerating devices that have already been enumerated.
> 
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Reviewed-by: Joey Lee <jlee@suse.com>

Thanka a lot!
Joey Lee

> ---
>  drivers/acpi/scan.c |    2 ++
>  1 file changed, 2 insertions(+)
> 
> Index: linux-pm/drivers/acpi/scan.c
> ===================================================================
> --- linux-pm.orig/drivers/acpi/scan.c
> +++ linux-pm/drivers/acpi/scan.c
> @@ -1850,6 +1850,8 @@ static void acpi_bus_attach(struct acpi_
>  			device->flags.power_manageable = 0;
>  
>  		device->flags.initialized = true;
> +	} else if (device->flags.visited) {
> +		goto ok;
>  	}
>  
>  	ret = acpi_scan_attach_handler(device);
> 
> --
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