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* [PATCH] ACPI: Remove the wakeup.run_wake_count device field
@ 2011-02-03 19:14 Rafael J. Wysocki
  2011-02-03 19:20 ` Jesse Barnes
  2011-02-03 19:20 ` Jesse Barnes
  0 siblings, 2 replies; 4+ messages in thread
From: Rafael J. Wysocki @ 2011-02-03 19:14 UTC (permalink / raw)
  To: Len Brown
  Cc: Jesse Barnes, Matthew Garrett, Linux PM List, LKML,
	ACPI Devel Maling List, linux-pci

From: Rafael J. Wysocki <rjw@sisk.pl>

The wakeup.run_wake_count ACPI device field is only used by the PCI
runtime PM code to "protect" devices from being prepared for
generating wakeup signals more than once in a row.  However, it
really doesn't provide any protection, because (1) all of the
functions it is supposed to protect use their own reference counters
effectively ensuring that the device will be set up for generating
wakeup signals just once and (2) the PCI runtime PM code uses
wakeup.run_wake_count in a racy way, since nothing prevents
acpi_dev_run_wake() from being called concurrently from two different
threads for the same device.

Remove the wakeup.run_wake_count ACPI device field which is
unnecessary, confusing and used in a wrong way.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
---
 drivers/acpi/button.c   |    2 --
 drivers/acpi/scan.c     |    1 -
 drivers/pci/pci-acpi.c  |   16 ++++------------
 include/acpi/acpi_bus.h |    1 -
 4 files changed, 4 insertions(+), 16 deletions(-)

Index: linux-2.6/drivers/acpi/button.c
===================================================================
--- linux-2.6.orig/drivers/acpi/button.c
+++ linux-2.6/drivers/acpi/button.c
@@ -430,7 +430,6 @@ static int acpi_button_add(struct acpi_d
 		/* Button's GPE is run-wake GPE */
 		acpi_enable_gpe(device->wakeup.gpe_device,
 				device->wakeup.gpe_number);
-		device->wakeup.run_wake_count++;
 		device_set_wakeup_enable(&device->dev, true);
 	}
 
@@ -453,7 +452,6 @@ static int acpi_button_remove(struct acp
 	if (device->wakeup.flags.valid) {
 		acpi_disable_gpe(device->wakeup.gpe_device,
 				device->wakeup.gpe_number);
-		device->wakeup.run_wake_count--;
 		device_set_wakeup_enable(&device->dev, false);
 	}
 
Index: linux-2.6/drivers/acpi/scan.c
===================================================================
--- linux-2.6.orig/drivers/acpi/scan.c
+++ linux-2.6/drivers/acpi/scan.c
@@ -797,7 +797,6 @@ static void acpi_bus_set_run_wake_flags(
 	acpi_status status;
 	acpi_event_status event_status;
 
-	device->wakeup.run_wake_count = 0;
 	device->wakeup.flags.notifier_present = 0;
 
 	/* Power button, Lid switch always enable wakeup */
Index: linux-2.6/drivers/pci/pci-acpi.c
===================================================================
--- linux-2.6.orig/drivers/pci/pci-acpi.c
+++ linux-2.6/drivers/pci/pci-acpi.c
@@ -293,19 +293,11 @@ static int acpi_dev_run_wake(struct devi
 	}
 
 	if (enable) {
-		if (!dev->wakeup.run_wake_count++) {
-			acpi_enable_wakeup_device_power(dev, ACPI_STATE_S0);
-			acpi_enable_gpe(dev->wakeup.gpe_device,
-					dev->wakeup.gpe_number);
-		}
-	} else if (dev->wakeup.run_wake_count > 0) {
-		if (!--dev->wakeup.run_wake_count) {
-			acpi_disable_gpe(dev->wakeup.gpe_device,
-					 dev->wakeup.gpe_number);
-			acpi_disable_wakeup_device_power(dev);
-		}
+		acpi_enable_wakeup_device_power(dev, ACPI_STATE_S0);
+		acpi_enable_gpe(dev->wakeup.gpe_device, dev->wakeup.gpe_number);
 	} else {
-		error = -EALREADY;
+		acpi_disable_gpe(dev->wakeup.gpe_device, dev->wakeup.gpe_number);
+		acpi_disable_wakeup_device_power(dev);
 	}
 
 	return error;
Index: linux-2.6/include/acpi/acpi_bus.h
===================================================================
--- linux-2.6.orig/include/acpi/acpi_bus.h
+++ linux-2.6/include/acpi/acpi_bus.h
@@ -250,7 +250,6 @@ struct acpi_device_wakeup {
 	struct acpi_handle_list resources;
 	struct acpi_device_wakeup_flags flags;
 	int prepare_count;
-	int run_wake_count;
 };
 
 /* Device */

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH] ACPI: Remove the wakeup.run_wake_count device field
  2011-02-03 19:14 [PATCH] ACPI: Remove the wakeup.run_wake_count device field Rafael J. Wysocki
@ 2011-02-03 19:20 ` Jesse Barnes
  2011-02-03 19:20 ` Jesse Barnes
  1 sibling, 0 replies; 4+ messages in thread
From: Jesse Barnes @ 2011-02-03 19:20 UTC (permalink / raw)
  To: Rafael J. Wysocki
  Cc: Len Brown, Matthew Garrett, Linux PM List, LKML,
	ACPI Devel Maling List, linux-pci

On Thu, 3 Feb 2011 20:14:17 +0100
"Rafael J. Wysocki" <rjw@sisk.pl> wrote:

> From: Rafael J. Wysocki <rjw@sisk.pl>
> 
> The wakeup.run_wake_count ACPI device field is only used by the PCI
> runtime PM code to "protect" devices from being prepared for
> generating wakeup signals more than once in a row.  However, it
> really doesn't provide any protection, because (1) all of the
> functions it is supposed to protect use their own reference counters
> effectively ensuring that the device will be set up for generating
> wakeup signals just once and (2) the PCI runtime PM code uses
> wakeup.run_wake_count in a racy way, since nothing prevents
> acpi_dev_run_wake() from being called concurrently from two different
> threads for the same device.
> 
> Remove the wakeup.run_wake_count ACPI device field which is
> unnecessary, confusing and used in a wrong way.
> 
> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
> ---
>  drivers/acpi/button.c   |    2 --
>  drivers/acpi/scan.c     |    1 -
>  drivers/pci/pci-acpi.c  |   16 ++++------------
>  include/acpi/acpi_bus.h |    1 -
>  4 files changed, 4 insertions(+), 16 deletions(-)

Ack on the PCI bits.

Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>

-- 
Jesse Barnes, Intel Open Source Technology Center

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH] ACPI: Remove the wakeup.run_wake_count device field
  2011-02-03 19:14 [PATCH] ACPI: Remove the wakeup.run_wake_count device field Rafael J. Wysocki
  2011-02-03 19:20 ` Jesse Barnes
@ 2011-02-03 19:20 ` Jesse Barnes
  1 sibling, 0 replies; 4+ messages in thread
From: Jesse Barnes @ 2011-02-03 19:20 UTC (permalink / raw)
  To: Rafael J. Wysocki; +Cc: linux-pci, LKML, ACPI Devel Maling List, Linux PM List

On Thu, 3 Feb 2011 20:14:17 +0100
"Rafael J. Wysocki" <rjw@sisk.pl> wrote:

> From: Rafael J. Wysocki <rjw@sisk.pl>
> 
> The wakeup.run_wake_count ACPI device field is only used by the PCI
> runtime PM code to "protect" devices from being prepared for
> generating wakeup signals more than once in a row.  However, it
> really doesn't provide any protection, because (1) all of the
> functions it is supposed to protect use their own reference counters
> effectively ensuring that the device will be set up for generating
> wakeup signals just once and (2) the PCI runtime PM code uses
> wakeup.run_wake_count in a racy way, since nothing prevents
> acpi_dev_run_wake() from being called concurrently from two different
> threads for the same device.
> 
> Remove the wakeup.run_wake_count ACPI device field which is
> unnecessary, confusing and used in a wrong way.
> 
> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
> ---
>  drivers/acpi/button.c   |    2 --
>  drivers/acpi/scan.c     |    1 -
>  drivers/pci/pci-acpi.c  |   16 ++++------------
>  include/acpi/acpi_bus.h |    1 -
>  4 files changed, 4 insertions(+), 16 deletions(-)

Ack on the PCI bits.

Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>

-- 
Jesse Barnes, Intel Open Source Technology Center

^ permalink raw reply	[flat|nested] 4+ messages in thread

* [PATCH] ACPI: Remove the wakeup.run_wake_count device field
@ 2011-02-03 19:14 Rafael J. Wysocki
  0 siblings, 0 replies; 4+ messages in thread
From: Rafael J. Wysocki @ 2011-02-03 19:14 UTC (permalink / raw)
  To: Len Brown
  Cc: linux-pci, LKML, Jesse Barnes, ACPI Devel Maling List, Linux PM List

From: Rafael J. Wysocki <rjw@sisk.pl>

The wakeup.run_wake_count ACPI device field is only used by the PCI
runtime PM code to "protect" devices from being prepared for
generating wakeup signals more than once in a row.  However, it
really doesn't provide any protection, because (1) all of the
functions it is supposed to protect use their own reference counters
effectively ensuring that the device will be set up for generating
wakeup signals just once and (2) the PCI runtime PM code uses
wakeup.run_wake_count in a racy way, since nothing prevents
acpi_dev_run_wake() from being called concurrently from two different
threads for the same device.

Remove the wakeup.run_wake_count ACPI device field which is
unnecessary, confusing and used in a wrong way.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
---
 drivers/acpi/button.c   |    2 --
 drivers/acpi/scan.c     |    1 -
 drivers/pci/pci-acpi.c  |   16 ++++------------
 include/acpi/acpi_bus.h |    1 -
 4 files changed, 4 insertions(+), 16 deletions(-)

Index: linux-2.6/drivers/acpi/button.c
===================================================================
--- linux-2.6.orig/drivers/acpi/button.c
+++ linux-2.6/drivers/acpi/button.c
@@ -430,7 +430,6 @@ static int acpi_button_add(struct acpi_d
 		/* Button's GPE is run-wake GPE */
 		acpi_enable_gpe(device->wakeup.gpe_device,
 				device->wakeup.gpe_number);
-		device->wakeup.run_wake_count++;
 		device_set_wakeup_enable(&device->dev, true);
 	}
 
@@ -453,7 +452,6 @@ static int acpi_button_remove(struct acp
 	if (device->wakeup.flags.valid) {
 		acpi_disable_gpe(device->wakeup.gpe_device,
 				device->wakeup.gpe_number);
-		device->wakeup.run_wake_count--;
 		device_set_wakeup_enable(&device->dev, false);
 	}
 
Index: linux-2.6/drivers/acpi/scan.c
===================================================================
--- linux-2.6.orig/drivers/acpi/scan.c
+++ linux-2.6/drivers/acpi/scan.c
@@ -797,7 +797,6 @@ static void acpi_bus_set_run_wake_flags(
 	acpi_status status;
 	acpi_event_status event_status;
 
-	device->wakeup.run_wake_count = 0;
 	device->wakeup.flags.notifier_present = 0;
 
 	/* Power button, Lid switch always enable wakeup */
Index: linux-2.6/drivers/pci/pci-acpi.c
===================================================================
--- linux-2.6.orig/drivers/pci/pci-acpi.c
+++ linux-2.6/drivers/pci/pci-acpi.c
@@ -293,19 +293,11 @@ static int acpi_dev_run_wake(struct devi
 	}
 
 	if (enable) {
-		if (!dev->wakeup.run_wake_count++) {
-			acpi_enable_wakeup_device_power(dev, ACPI_STATE_S0);
-			acpi_enable_gpe(dev->wakeup.gpe_device,
-					dev->wakeup.gpe_number);
-		}
-	} else if (dev->wakeup.run_wake_count > 0) {
-		if (!--dev->wakeup.run_wake_count) {
-			acpi_disable_gpe(dev->wakeup.gpe_device,
-					 dev->wakeup.gpe_number);
-			acpi_disable_wakeup_device_power(dev);
-		}
+		acpi_enable_wakeup_device_power(dev, ACPI_STATE_S0);
+		acpi_enable_gpe(dev->wakeup.gpe_device, dev->wakeup.gpe_number);
 	} else {
-		error = -EALREADY;
+		acpi_disable_gpe(dev->wakeup.gpe_device, dev->wakeup.gpe_number);
+		acpi_disable_wakeup_device_power(dev);
 	}
 
 	return error;
Index: linux-2.6/include/acpi/acpi_bus.h
===================================================================
--- linux-2.6.orig/include/acpi/acpi_bus.h
+++ linux-2.6/include/acpi/acpi_bus.h
@@ -250,7 +250,6 @@ struct acpi_device_wakeup {
 	struct acpi_handle_list resources;
 	struct acpi_device_wakeup_flags flags;
 	int prepare_count;
-	int run_wake_count;
 };
 
 /* Device */

^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2011-02-03 19:20 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2011-02-03 19:14 [PATCH] ACPI: Remove the wakeup.run_wake_count device field Rafael J. Wysocki
2011-02-03 19:20 ` Jesse Barnes
2011-02-03 19:20 ` Jesse Barnes
2011-02-03 19:14 Rafael J. Wysocki

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