[PATCH] Clear WAK_STS on resume

[PATCH] Clear WAK_STS on resume

[Matthew Garrett]

The leading other brand OS appears to clear the WAK_STS flag on resume. 
When rebooted, certain BIOSes assume that the system is actually 
resuming if it's still set and so fail to reboot correctly. Make sure 
that it's cleared at resume time.

Signed-off-by: Matthew Garrett <mjg@redhat.com>

---

I've had it confirmed by AMI that some of their BIOSes make this 
assumption - there may well be others out there as well.

diff --git a/drivers/acpi/hardware/hwsleep.c b/drivers/acpi/hardware/hwsleep.c
index dba3cfb..1cda856 100644
--- a/drivers/acpi/hardware/hwsleep.c
+++ b/drivers/acpi/hardware/hwsleep.c
@@ -627,6 +627,9 @@ acpi_status acpi_leave_sleep_state(u8 sleep_state)
 	}
 	/* TBD: _WAK "sometimes" returns stuff - do we want to look at it? */
 
+	/* Clear wake status */
+	acpi_set_register(ACPI_BITREG_WAKE_STATUS, 1);
+
 	acpi_gbl_system_awake_and_running = TRUE;
 
 	/* Enable power button */

-- 
Matthew Garrett | mjg59@srcf.ucam.org

RE: [PATCH] Clear WAK_STS on resume

[Moore, Robert]

Hey, why not:

/*
 * The leading other brand OS appears to clear the WAK_STS flag on
resume.
 * When rebooted, certain BIOSes assume that the system is actually
 * resuming if it's still set and so fail to reboot correctly. Make sure
 * that it's cleared at resume time.
 */
 acpi_set_register(ACPI_BITREG_WAKE_STATUS, 1);

>-----Original Message-----
>From: linux-acpi-owner@vger.kernel.org [mailto:linux-acpi-
>owner@vger.kernel.org] On Behalf Of Matthew Garrett
>Sent: Wednesday, August 06, 2008 10:58 AM
>To: linux-acpi@vger.kernel.org
>Cc: Brown, Len; pavel@suse.cz; rjw@sisk.pl; ak@linux.intel.com
>Subject: [PATCH] Clear WAK_STS on resume
>
>The leading other brand OS appears to clear the WAK_STS flag on resume.
>When rebooted, certain BIOSes assume that the system is actually
>resuming if it's still set and so fail to reboot correctly. Make sure
>that it's cleared at resume time.
>
>Signed-off-by: Matthew Garrett <mjg@redhat.com>
>
>---
>
>I've had it confirmed by AMI that some of their BIOSes make this
>assumption - there may well be others out there as well.
>
>diff --git a/drivers/acpi/hardware/hwsleep.c
>b/drivers/acpi/hardware/hwsleep.c
>index dba3cfb..1cda856 100644
>--- a/drivers/acpi/hardware/hwsleep.c
>+++ b/drivers/acpi/hardware/hwsleep.c
>@@ -627,6 +627,9 @@ acpi_status acpi_leave_sleep_state(u8 sleep_state)
> 	}
> 	/* TBD: _WAK "sometimes" returns stuff - do we want to look at
it? */
>
>+	/* Clear wake status */
>+	acpi_set_register(ACPI_BITREG_WAKE_STATUS, 1);
>+
> 	acpi_gbl_system_awake_and_running = TRUE;
>
> 	/* Enable power button */
>
>--
>Matthew Garrett | mjg59@srcf.ucam.org
>--
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Re: [PATCH] Clear WAK_STS on resume

[Matthew Garrett]

The leading other brand OS appears to clear the WAK_STS flag on resume.                                                                                                                                
When rebooted, certain BIOSes assume that the system is actually                                                                                                                                       
resuming if it's still set and so fail to reboot correctly. Make sure                                                                                                                                  
that it's cleared at resume time.                                                                                                                                                                      
                                                                                                                                                                                                       
Signed-off-by: Matthew Garrett <mjg@redhat.com>                                                                                                                                                        
                            
---

Comment clarified as suggested by Bob Moore

diff --git a/drivers/acpi/hardware/hwsleep.c b/drivers/acpi/hardware/hwsleep.c
index dba3cfb..130a44b 100644
--- a/drivers/acpi/hardware/hwsleep.c
+++ b/drivers/acpi/hardware/hwsleep.c
@@ -627,6 +627,13 @@ acpi_status acpi_leave_sleep_state(u8 sleep_state)
 	}
 	/* TBD: _WAK "sometimes" returns stuff - do we want to look at it? */
 
+	/*
+	 * Some BIOSes assume that WAK_STS will be cleared on resume and use
+	 * it to determine whether the system is rebooting or resuming. Clear
+	 * it for compatibility.
+	 */
+	acpi_set_register(ACPI_BITREG_WAKE_STATUS, 1);
+
 	acpi_gbl_system_awake_and_running = TRUE;
 
 	/* Enable power button */

-- 
Matthew Garrett | mjg59@srcf.ucam.org

Re: [PATCH] Clear WAK_STS on resume

[Andi Kleen]

Matthew Garrett wrote:
> The leading other brand OS appears to clear the WAK_STS flag on resume. 
> When rebooted, certain BIOSes assume that the system is actually 
> resuming if it's still set and so fail to reboot correctly. Make sure 
> that it's cleared at resume time.

Queued for test thanks.

-Andi

Re: [PATCH] Clear WAK_STS on resume

[Thomas Renninger]

On Monday 11 August 2008 13:25:15 Andi Kleen wrote:
> Matthew Garrett wrote:
> > The leading other brand OS appears to clear the WAK_STS flag on resume.
> > When rebooted, certain BIOSes assume that the system is actually
> > resuming if it's still set and so fail to reboot correctly. Make sure
> > that it's cleared at resume time.
>
> Queued for test thanks.

This sounds like a bug fix, depending on what "fail to reboot correctly" 
exactly means, it sounds like a critical bug.
Shouldn't this still be queued for .27?
Test means for next .28-rc1 cycle?

       Thomas