diff mbox series

[SRU,Artful/linux-oem,1/1] ACPI / PM: Allow deeper wakeup power states with no _SxD nor _SxW

Message ID 20180328085530.8453-2-kai.heng.feng@canonical.com
State Accepted
Headers show
Series Fix an issue that when system in S3, USB keyboard can't wake up the system. | expand

Commit Message

Kai-Heng Feng March 28, 2018, 8:55 a.m. UTC 
From: Daniel Drake <drake@endlessm.com>

BugLink: https://bugs.launchpad.net/bugs/1759511

acpi_dev_pm_get_state() is used to determine the range of allowable
device power states when going into S3 suspend. This is implemented
by executing the _S3D and _S3W ACPI methods.

Linux follows the ACPI spec behaviour in that when _S3D is implemented
and _S3W is not, Linux will not go into a power state deeper than the one
returned by _S3D for a wakeup-enabled device.

However, this same logic is being applied to the case when neither
_S3D nor _S3W are present, and the result is that this function
decides that the device must stay in D0 (fully on) state.

This is breaking USB wakeups on Asus V222GA and Acer XC-830. _S3D and
_S3W are not present, so the USB controller is left in the D0 running
state during S3, and hence it is unable to generate a PME# wake event.

The ACPI spec is unclear on which power states are permissable for
wakeup-enabled devices when both _S3D and _S3W are missing.
However, USB wakeups work fine on these platforms under Windows, where
device manager shows that they are using D3 device state for the USB
controller in S3.

I assume that the "max = min" clamping done by the code here is
specifically written for the _S3D but no _S3W case. By making the
code true to those conditions, avoiding them on these platforms,
the controller will be put into D3 state and USB wakeups start working.

Additionally I feel that this change makes the code more directly
mirror the wording of the ACPI spec and it's associated lack of clarity.

Thanks to Mathias Nyman for pointing us in the right direction.

Signed-off-by: Daniel Drake <drake@endlessm.com>
Link: http://lkml.kernel.org/r/CAB4CAwf_k-WsF3zL4epm9TKAOu0h=Bv1XhXV_gY3bziOo_NPKA@mail.gmail.com

https://phabricator.endlessm.com/T21410
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
(cherry picked from commit bf8c6184e0c3d4d5e005e085e9f96f478a267b20 git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git linux-next)
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
---
 drivers/acpi/device_pm.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

Comments

Stefan Bader March 28, 2018, 12:50 p.m. UTC | #1 
On 28.03.2018 10:55, Kai-Heng Feng wrote:
> From: Daniel Drake <drake@endlessm.com>
> 
> BugLink: https://bugs.launchpad.net/bugs/1759511
> 
> acpi_dev_pm_get_state() is used to determine the range of allowable
> device power states when going into S3 suspend. This is implemented
> by executing the _S3D and _S3W ACPI methods.
> 
> Linux follows the ACPI spec behaviour in that when _S3D is implemented
> and _S3W is not, Linux will not go into a power state deeper than the one
> returned by _S3D for a wakeup-enabled device.
> 
> However, this same logic is being applied to the case when neither
> _S3D nor _S3W are present, and the result is that this function
> decides that the device must stay in D0 (fully on) state.
> 
> This is breaking USB wakeups on Asus V222GA and Acer XC-830. _S3D and
> _S3W are not present, so the USB controller is left in the D0 running
> state during S3, and hence it is unable to generate a PME# wake event.
> 
> The ACPI spec is unclear on which power states are permissable for
> wakeup-enabled devices when both _S3D and _S3W are missing.
> However, USB wakeups work fine on these platforms under Windows, where
> device manager shows that they are using D3 device state for the USB
> controller in S3.
> 
> I assume that the "max = min" clamping done by the code here is
> specifically written for the _S3D but no _S3W case. By making the
> code true to those conditions, avoiding them on these platforms,
> the controller will be put into D3 state and USB wakeups start working.
> 
> Additionally I feel that this change makes the code more directly
> mirror the wording of the ACPI spec and it's associated lack of clarity.
> 
> Thanks to Mathias Nyman for pointing us in the right direction.
> 
> Signed-off-by: Daniel Drake <drake@endlessm.com>
> Link: http://lkml.kernel.org/r/CAB4CAwf_k-WsF3zL4epm9TKAOu0h=Bv1XhXV_gY3bziOo_NPKA@mail.gmail.com
> 
> https://phabricator.endlessm.com/T21410
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> (cherry picked from commit bf8c6184e0c3d4d5e005e085e9f96f478a267b20 git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git linux-next)
> Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com>

> ---

Since this is pulled from linux-next, I would suspect this is also wanted in
Bionic, right?

>  drivers/acpi/device_pm.c | 11 ++++++++++-
>  1 file changed, 10 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/acpi/device_pm.c b/drivers/acpi/device_pm.c
> index 2ed6935d4483..5bb754b1ccb2 100644
> --- a/drivers/acpi/device_pm.c
> +++ b/drivers/acpi/device_pm.c
> @@ -534,6 +534,7 @@ static int acpi_dev_pm_get_state(struct device *dev, struct acpi_device *adev,
>  	unsigned long long ret;
>  	int d_min, d_max;
>  	bool wakeup = false;
> +	bool has_sxd = false;
>  	acpi_status status;
>  
>  	/*
> @@ -572,6 +573,10 @@ static int acpi_dev_pm_get_state(struct device *dev, struct acpi_device *adev,
>  			else
>  				return -ENODATA;
>  		}
> +
> +		if (status == AE_OK)
> +			has_sxd = true;
> +
>  		d_min = ret;
>  		wakeup = device_may_wakeup(dev) && adev->wakeup.flags.valid
>  			&& adev->wakeup.sleep_state >= target_state;
> @@ -591,7 +596,11 @@ static int acpi_dev_pm_get_state(struct device *dev, struct acpi_device *adev,
>  		method[3] = 'W';
>  		status = acpi_evaluate_integer(handle, method, NULL, &ret);
>  		if (status == AE_NOT_FOUND) {
> -			if (target_state > ACPI_STATE_S0)
> +			/* No _SxW. In this case, the ACPI spec says that we
> +			 * must not go into any power state deeper than the
> +			 * value returned from _SxD.
> +			 */
> +			if (has_sxd && target_state > ACPI_STATE_S0)
>  				d_max = d_min;
>  		} else if (ACPI_SUCCESS(status) && ret <= ACPI_STATE_D3_COLD) {
>  			/* Fall back to D3cold if ret is not a valid state. */
>
Kai-Heng Feng March 28, 2018, 3:58 p.m. UTC | #2 
Stefan Bader <stefan.bader@canonical.com> wrote:

> On 28.03.2018 10:55, Kai-Heng Feng wrote:
>> From: Daniel Drake <drake@endlessm.com>
>>
>> BugLink: https://bugs.launchpad.net/bugs/1759511
>>
>> acpi_dev_pm_get_state() is used to determine the range of allowable
>> device power states when going into S3 suspend. This is implemented
>> by executing the _S3D and _S3W ACPI methods.
>>
>> Linux follows the ACPI spec behaviour in that when _S3D is implemented
>> and _S3W is not, Linux will not go into a power state deeper than the one
>> returned by _S3D for a wakeup-enabled device.
>>
>> However, this same logic is being applied to the case when neither
>> _S3D nor _S3W are present, and the result is that this function
>> decides that the device must stay in D0 (fully on) state.
>>
>> This is breaking USB wakeups on Asus V222GA and Acer XC-830. _S3D and
>> _S3W are not present, so the USB controller is left in the D0 running
>> state during S3, and hence it is unable to generate a PME# wake event.
>>
>> The ACPI spec is unclear on which power states are permissable for
>> wakeup-enabled devices when both _S3D and _S3W are missing.
>> However, USB wakeups work fine on these platforms under Windows, where
>> device manager shows that they are using D3 device state for the USB
>> controller in S3.
>>
>> I assume that the "max = min" clamping done by the code here is
>> specifically written for the _S3D but no _S3W case. By making the
>> code true to those conditions, avoiding them on these platforms,
>> the controller will be put into D3 state and USB wakeups start working.
>>
>> Additionally I feel that this change makes the code more directly
>> mirror the wording of the ACPI spec and it's associated lack of clarity.
>>
>> Thanks to Mathias Nyman for pointing us in the right direction.
>>
>> Signed-off-by: Daniel Drake <drake@endlessm.com>
>> Link:  
>> http://lkml.kernel.org/r/CAB4CAwf_k-WsF3zL4epm9TKAOu0h=Bv1XhXV_gY3bziOo_NPKA@mail.gmail.com
>>
>> https://phabricator.endlessm.com/T21410
>> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
>> (cherry picked from commit bf8c6184e0c3d4d5e005e085e9f96f478a267b20  
>> git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git  
>> linux-next)
>> Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
> Acked-by: Stefan Bader <stefan.bader@canonical.com>
>
>> ---
>
> Since this is pulled from linux-next, I would suspect this is also wanted  
> in
> Bionic, right?

This patch should be included for all linux version.
I planed to ask linux-stable to include the patch once it's in Linus' tree,  
so we will get this patch through stable update.

Kai-Heng

>
>> drivers/acpi/device_pm.c | 11 ++++++++++-
>>  1 file changed, 10 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/acpi/device_pm.c b/drivers/acpi/device_pm.c
>> index 2ed6935d4483..5bb754b1ccb2 100644
>> --- a/drivers/acpi/device_pm.c
>> +++ b/drivers/acpi/device_pm.c
>> @@ -534,6 +534,7 @@ static int acpi_dev_pm_get_state(struct device *dev,  
>> struct acpi_device *adev,
>>  	unsigned long long ret;
>>  	int d_min, d_max;
>>  	bool wakeup = false;
>> +	bool has_sxd = false;
>>  	acpi_status status;
>>
>>  	/*
>> @@ -572,6 +573,10 @@ static int acpi_dev_pm_get_state(struct device  
>> *dev, struct acpi_device *adev,
>>  			else
>>  				return -ENODATA;
>>  		}
>> +
>> +		if (status == AE_OK)
>> +			has_sxd = true;
>> +
>>  		d_min = ret;
>>  		wakeup = device_may_wakeup(dev) && adev->wakeup.flags.valid
>>  			&& adev->wakeup.sleep_state >= target_state;
>> @@ -591,7 +596,11 @@ static int acpi_dev_pm_get_state(struct device  
>> *dev, struct acpi_device *adev,
>>  		method[3] = 'W';
>>  		status = acpi_evaluate_integer(handle, method, NULL, &ret);
>>  		if (status == AE_NOT_FOUND) {
>> -			if (target_state > ACPI_STATE_S0)
>> +			/* No _SxW. In this case, the ACPI spec says that we
>> +			 * must not go into any power state deeper than the
>> +			 * value returned from _SxD.
>> +			 */
>> +			if (has_sxd && target_state > ACPI_STATE_S0)
>>  				d_max = d_min;
>>  		} else if (ACPI_SUCCESS(status) && ret <= ACPI_STATE_D3_COLD) {
>>  			/* Fall back to D3cold if ret is not a valid state. */
Seth Forshee March 28, 2018, 4:42 p.m. UTC | #3 
On Wed, Mar 28, 2018 at 11:58:16PM +0800, Kai-Heng Feng wrote:
> Stefan Bader <stefan.bader@canonical.com> wrote:
> 
> > On 28.03.2018 10:55, Kai-Heng Feng wrote:
> > > From: Daniel Drake <drake@endlessm.com>
> > > 
> > > BugLink: https://bugs.launchpad.net/bugs/1759511
> > > 
> > > acpi_dev_pm_get_state() is used to determine the range of allowable
> > > device power states when going into S3 suspend. This is implemented
> > > by executing the _S3D and _S3W ACPI methods.
> > > 
> > > Linux follows the ACPI spec behaviour in that when _S3D is implemented
> > > and _S3W is not, Linux will not go into a power state deeper than the one
> > > returned by _S3D for a wakeup-enabled device.
> > > 
> > > However, this same logic is being applied to the case when neither
> > > _S3D nor _S3W are present, and the result is that this function
> > > decides that the device must stay in D0 (fully on) state.
> > > 
> > > This is breaking USB wakeups on Asus V222GA and Acer XC-830. _S3D and
> > > _S3W are not present, so the USB controller is left in the D0 running
> > > state during S3, and hence it is unable to generate a PME# wake event.
> > > 
> > > The ACPI spec is unclear on which power states are permissable for
> > > wakeup-enabled devices when both _S3D and _S3W are missing.
> > > However, USB wakeups work fine on these platforms under Windows, where
> > > device manager shows that they are using D3 device state for the USB
> > > controller in S3.
> > > 
> > > I assume that the "max = min" clamping done by the code here is
> > > specifically written for the _S3D but no _S3W case. By making the
> > > code true to those conditions, avoiding them on these platforms,
> > > the controller will be put into D3 state and USB wakeups start working.
> > > 
> > > Additionally I feel that this change makes the code more directly
> > > mirror the wording of the ACPI spec and it's associated lack of clarity.
> > > 
> > > Thanks to Mathias Nyman for pointing us in the right direction.
> > > 
> > > Signed-off-by: Daniel Drake <drake@endlessm.com>
> > > Link: http://lkml.kernel.org/r/CAB4CAwf_k-WsF3zL4epm9TKAOu0h=Bv1XhXV_gY3bziOo_NPKA@mail.gmail.com
> > > 
> > > https://phabricator.endlessm.com/T21410
> > > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> > > (cherry picked from commit bf8c6184e0c3d4d5e005e085e9f96f478a267b20
> > > git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git
> > > linux-next)
> > > Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
> > Acked-by: Stefan Bader <stefan.bader@canonical.com>
> > 
> > > ---
> > 
> > Since this is pulled from linux-next, I would suspect this is also
> > wanted in
> > Bionic, right?
> 
> This patch should be included for all linux version.
> I planed to ask linux-stable to include the patch once it's in Linus' tree,
> so we will get this patch through stable update.

We should go ahead and get it into bionic anyway. Applied to
bionic/master-next.
diff mbox series

Patch

diff --git a/drivers/acpi/device_pm.c b/drivers/acpi/device_pm.c
index 2ed6935d4483..5bb754b1ccb2 100644
--- a/drivers/acpi/device_pm.c
+++ b/drivers/acpi/device_pm.c
@@ -534,6 +534,7 @@  static int acpi_dev_pm_get_state(struct device *dev, struct acpi_device *adev,
 	unsigned long long ret;
 	int d_min, d_max;
 	bool wakeup = false;
+	bool has_sxd = false;
 	acpi_status status;
 
 	/*
@@ -572,6 +573,10 @@  static int acpi_dev_pm_get_state(struct device *dev, struct acpi_device *adev,
 			else
 				return -ENODATA;
 		}
+
+		if (status == AE_OK)
+			has_sxd = true;
+
 		d_min = ret;
 		wakeup = device_may_wakeup(dev) && adev->wakeup.flags.valid
 			&& adev->wakeup.sleep_state >= target_state;
@@ -591,7 +596,11 @@  static int acpi_dev_pm_get_state(struct device *dev, struct acpi_device *adev,
 		method[3] = 'W';
 		status = acpi_evaluate_integer(handle, method, NULL, &ret);
 		if (status == AE_NOT_FOUND) {
-			if (target_state > ACPI_STATE_S0)
+			/* No _SxW. In this case, the ACPI spec says that we
+			 * must not go into any power state deeper than the
+			 * value returned from _SxD.
+			 */
+			if (has_sxd && target_state > ACPI_STATE_S0)
 				d_max = d_min;
 		} else if (ACPI_SUCCESS(status) && ret <= ACPI_STATE_D3_COLD) {
 			/* Fall back to D3cold if ret is not a valid state. */