[2/3] ACPICA: Make it possible to enable runtime GPEs earlier

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

Runtime GPEs have corresponding _Lxx/_Exx methods and are enabled
automatically during the initialization of the ACPI subsystem through
acpi_update_all_gpes() with the assumption that acpi_setup_gpe_for_wake()
will be called in advance for all of the GPEs pointed to by _PRW
objects in the namespace that may be affected by acpi_update_all_gpes().
That is, acpi_ev_initialize_gpe_block() can only be called for a GPE
block after acpi_setup_gpe_for_wake() has been called for all of the
_PRW (wakeup) GPEs in it.

The platform firmware on some systems, however, expects GPEs to be
enabled before the enumeration of devices which is when
acpi_setup_gpe_for_wake() is called and that goes against the above
assumption.

For this reason, introduce a new flag to be set by
acpi_ev_initialize_gpe_block() when automatically enabling a GPE
to indicate to acpi_setup_gpe_for_wake() that it needs to drop the
reference to the GPE coming from acpi_ev_initialize_gpe_block()
and modify acpi_setup_gpe_for_wake() accordingly.  These changes
allow acpi_setup_gpe_for_wake() and acpi_ev_initialize_gpe_block()
to be invoked in any order.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
 drivers/acpi/acpica/evgpeblk.c |    2 ++
 drivers/acpi/acpica/evxfgpe.c  |    8 ++++++++
 include/acpi/actypes.h         |    3 ++-
 3 files changed, 12 insertions(+), 1 deletion(-)

Hi, Rafael

For this patch, I have a concern.

> From: Rafael J. Wysocki [mailto:rjw@rjwysocki.net]
> Subject: [PATCH 2/3] ACPICA: Make it possible to enable runtime GPEs earlier
> 
> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> 
> Runtime GPEs have corresponding _Lxx/_Exx methods and are enabled
> automatically during the initialization of the ACPI subsystem through
> acpi_update_all_gpes() with the assumption that acpi_setup_gpe_for_wake()
> will be called in advance for all of the GPEs pointed to by _PRW
> objects in the namespace that may be affected by acpi_update_all_gpes().
> That is, acpi_ev_initialize_gpe_block() can only be called for a GPE
> block after acpi_setup_gpe_for_wake() has been called for all of the
> _PRW (wakeup) GPEs in it.
> 
> The platform firmware on some systems, however, expects GPEs to be
> enabled before the enumeration of devices which is when
> acpi_setup_gpe_for_wake() is called and that goes against the above
> assumption.
> 
> For this reason, introduce a new flag to be set by
> acpi_ev_initialize_gpe_block() when automatically enabling a GPE
> to indicate to acpi_setup_gpe_for_wake() that it needs to drop the
> reference to the GPE coming from acpi_ev_initialize_gpe_block()
> and modify acpi_setup_gpe_for_wake() accordingly.  These changes
> allow acpi_setup_gpe_for_wake() and acpi_ev_initialize_gpe_block()
> to be invoked in any order.
> 
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> ---
>  drivers/acpi/acpica/evgpeblk.c |    2 ++
>  drivers/acpi/acpica/evxfgpe.c  |    8 ++++++++
>  include/acpi/actypes.h         |    3 ++-
>  3 files changed, 12 insertions(+), 1 deletion(-)
> 
> Index: linux-pm/drivers/acpi/acpica/evgpeblk.c
> ===================================================================
> --- linux-pm.orig/drivers/acpi/acpica/evgpeblk.c
> +++ linux-pm/drivers/acpi/acpica/evgpeblk.c
> @@ -496,6 +496,8 @@ acpi_ev_initialize_gpe_block(struct acpi
>  				continue;
>  			}
> 
> +			gpe_event_info->flags |= ACPI_GPE_AUTO_ENABLED;
> +
>  			if (event_status & ACPI_EVENT_FLAG_STATUS_SET) {
>  				ACPI_INFO(("GPE 0x%02X active on init",
>  					   gpe_number));
> Index: linux-pm/include/acpi/actypes.h
> ===================================================================
> --- linux-pm.orig/include/acpi/actypes.h
> +++ linux-pm/include/acpi/actypes.h
> @@ -783,7 +783,7 @@ typedef u32 acpi_event_status;
>   *   |  | | |  +-- Type of dispatch:to method, handler, notify, or none
>   *   |  | | +----- Interrupt type: edge or level triggered
>   *   |  | +------- Is a Wake GPE
> - *   |  +--------- Is GPE masked by the software GPE masking mechanism
> + *   |  +--------- Has been enabled automatically at init time
>   *   +------------ <Reserved>
>   */
>  #define ACPI_GPE_DISPATCH_NONE          (u8) 0x00
> @@ -799,6 +799,7 @@ typedef u32 acpi_event_status;
>  #define ACPI_GPE_XRUPT_TYPE_MASK        (u8) 0x08
> 
>  #define ACPI_GPE_CAN_WAKE               (u8) 0x10
> +#define ACPI_GPE_AUTO_ENABLED           (u8) 0x20
> 
>  /*
>   * Flags for GPE and Lock interfaces
> Index: linux-pm/drivers/acpi/acpica/evxfgpe.c
> ===================================================================
> --- linux-pm.orig/drivers/acpi/acpica/evxfgpe.c
> +++ linux-pm/drivers/acpi/acpica/evxfgpe.c
> @@ -435,6 +435,14 @@ acpi_setup_gpe_for_wake(acpi_handle wake
>  		 */
>  		gpe_event_info->flags =
>  		    (ACPI_GPE_DISPATCH_NOTIFY | ACPI_GPE_LEVEL_TRIGGERED);
> +	} else if (gpe_event_info->flags & ACPI_GPE_AUTO_ENABLED) {
> +		/*
> +		 * A reference to this GPE has been added during the GPE block
> +		 * initialization, so drop it now to prevent the GPE from being
> +		 * permanently enabled and clear its ACPI_GPE_AUTO_ENABLED flag.
> +		 */
> +		(void)acpi_ev_remove_gpe_reference(gpe_event_info);
> +		gpe_event_info->flags &= ~ACPI_GPE_AUTO_ENABLED;

The problem is if the GPE is shared, how can we know decrement reference
once can sufficiently convert it into wakeup dispatcher owned GPE?

Thanks and best regards
Lv

On Thursday, August 10, 2017 3:52:05 AM CEST Zheng, Lv wrote:
> Hi, Rafael
> 
> For this patch, I have a concern.
> 
> > From: Rafael J. Wysocki [mailto:rjw@rjwysocki.net]
> > Subject: [PATCH 2/3] ACPICA: Make it possible to enable runtime GPEs earlier
> > 
> > From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> > 
> > Runtime GPEs have corresponding _Lxx/_Exx methods and are enabled
> > automatically during the initialization of the ACPI subsystem through
> > acpi_update_all_gpes() with the assumption that acpi_setup_gpe_for_wake()
> > will be called in advance for all of the GPEs pointed to by _PRW
> > objects in the namespace that may be affected by acpi_update_all_gpes().
> > That is, acpi_ev_initialize_gpe_block() can only be called for a GPE
> > block after acpi_setup_gpe_for_wake() has been called for all of the
> > _PRW (wakeup) GPEs in it.
> > 
> > The platform firmware on some systems, however, expects GPEs to be
> > enabled before the enumeration of devices which is when
> > acpi_setup_gpe_for_wake() is called and that goes against the above
> > assumption.
> > 
> > For this reason, introduce a new flag to be set by
> > acpi_ev_initialize_gpe_block() when automatically enabling a GPE
> > to indicate to acpi_setup_gpe_for_wake() that it needs to drop the
> > reference to the GPE coming from acpi_ev_initialize_gpe_block()
> > and modify acpi_setup_gpe_for_wake() accordingly.  These changes
> > allow acpi_setup_gpe_for_wake() and acpi_ev_initialize_gpe_block()
> > to be invoked in any order.
> > 
> > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> > ---
> >  drivers/acpi/acpica/evgpeblk.c |    2 ++
> >  drivers/acpi/acpica/evxfgpe.c  |    8 ++++++++
> >  include/acpi/actypes.h         |    3 ++-
> >  3 files changed, 12 insertions(+), 1 deletion(-)
> > 
> > Index: linux-pm/drivers/acpi/acpica/evgpeblk.c
> > ===================================================================
> > --- linux-pm.orig/drivers/acpi/acpica/evgpeblk.c
> > +++ linux-pm/drivers/acpi/acpica/evgpeblk.c
> > @@ -496,6 +496,8 @@ acpi_ev_initialize_gpe_block(struct acpi
> >  				continue;
> >  			}
> > 
> > +			gpe_event_info->flags |= ACPI_GPE_AUTO_ENABLED;
> > +
> >  			if (event_status & ACPI_EVENT_FLAG_STATUS_SET) {
> >  				ACPI_INFO(("GPE 0x%02X active on init",
> >  					   gpe_number));
> > Index: linux-pm/include/acpi/actypes.h
> > ===================================================================
> > --- linux-pm.orig/include/acpi/actypes.h
> > +++ linux-pm/include/acpi/actypes.h
> > @@ -783,7 +783,7 @@ typedef u32 acpi_event_status;
> >   *   |  | | |  +-- Type of dispatch:to method, handler, notify, or none
> >   *   |  | | +----- Interrupt type: edge or level triggered
> >   *   |  | +------- Is a Wake GPE
> > - *   |  +--------- Is GPE masked by the software GPE masking mechanism
> > + *   |  +--------- Has been enabled automatically at init time
> >   *   +------------ <Reserved>
> >   */
> >  #define ACPI_GPE_DISPATCH_NONE          (u8) 0x00
> > @@ -799,6 +799,7 @@ typedef u32 acpi_event_status;
> >  #define ACPI_GPE_XRUPT_TYPE_MASK        (u8) 0x08
> > 
> >  #define ACPI_GPE_CAN_WAKE               (u8) 0x10
> > +#define ACPI_GPE_AUTO_ENABLED           (u8) 0x20
> > 
> >  /*
> >   * Flags for GPE and Lock interfaces
> > Index: linux-pm/drivers/acpi/acpica/evxfgpe.c
> > ===================================================================
> > --- linux-pm.orig/drivers/acpi/acpica/evxfgpe.c
> > +++ linux-pm/drivers/acpi/acpica/evxfgpe.c
> > @@ -435,6 +435,14 @@ acpi_setup_gpe_for_wake(acpi_handle wake
> >  		 */
> >  		gpe_event_info->flags =
> >  		    (ACPI_GPE_DISPATCH_NOTIFY | ACPI_GPE_LEVEL_TRIGGERED);
> > +	} else if (gpe_event_info->flags & ACPI_GPE_AUTO_ENABLED) {
> > +		/*
> > +		 * A reference to this GPE has been added during the GPE block
> > +		 * initialization, so drop it now to prevent the GPE from being
> > +		 * permanently enabled and clear its ACPI_GPE_AUTO_ENABLED flag.
> > +		 */
> > +		(void)acpi_ev_remove_gpe_reference(gpe_event_info);
> > +		gpe_event_info->flags &= ~ACPI_GPE_AUTO_ENABLED;
> 
> The problem is if the GPE is shared, how can we know decrement reference
> once can sufficiently convert it into wakeup dispatcher owned GPE?

Even if it is shared, the current code will not enable it if it sees
ACPI_GPE_CAN_WAKE set.

We can change that logic, but that should be a separate patch IMO and
this is not related to the problem at hand.

Thanks,
Rafael

Hi,

> From: Rafael J. Wysocki [mailto:rjw@rjwysocki.net]
> Subject: Re: [PATCH 2/3] ACPICA: Make it possible to enable runtime GPEs earlier
> 
> On Thursday, August 10, 2017 3:52:05 AM CEST Zheng, Lv wrote:
> > Hi, Rafael
> >
> > For this patch, I have a concern.
> >
> > > From: Rafael J. Wysocki [mailto:rjw@rjwysocki.net]
> > > Subject: [PATCH 2/3] ACPICA: Make it possible to enable runtime GPEs earlier
> > >
> > > From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> > >
> > > Runtime GPEs have corresponding _Lxx/_Exx methods and are enabled
> > > automatically during the initialization of the ACPI subsystem through
> > > acpi_update_all_gpes() with the assumption that acpi_setup_gpe_for_wake()
> > > will be called in advance for all of the GPEs pointed to by _PRW
> > > objects in the namespace that may be affected by acpi_update_all_gpes().
> > > That is, acpi_ev_initialize_gpe_block() can only be called for a GPE
> > > block after acpi_setup_gpe_for_wake() has been called for all of the
> > > _PRW (wakeup) GPEs in it.
> > >
> > > The platform firmware on some systems, however, expects GPEs to be
> > > enabled before the enumeration of devices which is when
> > > acpi_setup_gpe_for_wake() is called and that goes against the above
> > > assumption.
> > >
> > > For this reason, introduce a new flag to be set by
> > > acpi_ev_initialize_gpe_block() when automatically enabling a GPE
> > > to indicate to acpi_setup_gpe_for_wake() that it needs to drop the
> > > reference to the GPE coming from acpi_ev_initialize_gpe_block()
> > > and modify acpi_setup_gpe_for_wake() accordingly.  These changes
> > > allow acpi_setup_gpe_for_wake() and acpi_ev_initialize_gpe_block()
> > > to be invoked in any order.
> > >
> > > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> > > ---
> > >  drivers/acpi/acpica/evgpeblk.c |    2 ++
> > >  drivers/acpi/acpica/evxfgpe.c  |    8 ++++++++
> > >  include/acpi/actypes.h         |    3 ++-
> > >  3 files changed, 12 insertions(+), 1 deletion(-)
> > >
> > > Index: linux-pm/drivers/acpi/acpica/evgpeblk.c
> > > ===================================================================
> > > --- linux-pm.orig/drivers/acpi/acpica/evgpeblk.c
> > > +++ linux-pm/drivers/acpi/acpica/evgpeblk.c
> > > @@ -496,6 +496,8 @@ acpi_ev_initialize_gpe_block(struct acpi
> > >  				continue;
> > >  			}
> > >
> > > +			gpe_event_info->flags |= ACPI_GPE_AUTO_ENABLED;
> > > +
> > >  			if (event_status & ACPI_EVENT_FLAG_STATUS_SET) {
> > >  				ACPI_INFO(("GPE 0x%02X active on init",
> > >  					   gpe_number));
> > > Index: linux-pm/include/acpi/actypes.h
> > > ===================================================================
> > > --- linux-pm.orig/include/acpi/actypes.h
> > > +++ linux-pm/include/acpi/actypes.h
> > > @@ -783,7 +783,7 @@ typedef u32 acpi_event_status;
> > >   *   |  | | |  +-- Type of dispatch:to method, handler, notify, or none
> > >   *   |  | | +----- Interrupt type: edge or level triggered
> > >   *   |  | +------- Is a Wake GPE
> > > - *   |  +--------- Is GPE masked by the software GPE masking mechanism
> > > + *   |  +--------- Has been enabled automatically at init time
> > >   *   +------------ <Reserved>
> > >   */
> > >  #define ACPI_GPE_DISPATCH_NONE          (u8) 0x00
> > > @@ -799,6 +799,7 @@ typedef u32 acpi_event_status;
> > >  #define ACPI_GPE_XRUPT_TYPE_MASK        (u8) 0x08
> > >
> > >  #define ACPI_GPE_CAN_WAKE               (u8) 0x10
> > > +#define ACPI_GPE_AUTO_ENABLED           (u8) 0x20
> > >
> > >  /*
> > >   * Flags for GPE and Lock interfaces
> > > Index: linux-pm/drivers/acpi/acpica/evxfgpe.c
> > > ===================================================================
> > > --- linux-pm.orig/drivers/acpi/acpica/evxfgpe.c
> > > +++ linux-pm/drivers/acpi/acpica/evxfgpe.c
> > > @@ -435,6 +435,14 @@ acpi_setup_gpe_for_wake(acpi_handle wake
> > >  		 */
> > >  		gpe_event_info->flags =
> > >  		    (ACPI_GPE_DISPATCH_NOTIFY | ACPI_GPE_LEVEL_TRIGGERED);
> > > +	} else if (gpe_event_info->flags & ACPI_GPE_AUTO_ENABLED) {
> > > +		/*
> > > +		 * A reference to this GPE has been added during the GPE block
> > > +		 * initialization, so drop it now to prevent the GPE from being
> > > +		 * permanently enabled and clear its ACPI_GPE_AUTO_ENABLED flag.
> > > +		 */
> > > +		(void)acpi_ev_remove_gpe_reference(gpe_event_info);
> > > +		gpe_event_info->flags &= ~ACPI_GPE_AUTO_ENABLED;
> >
> > The problem is if the GPE is shared, how can we know decrement reference
> > once can sufficiently convert it into wakeup dispatcher owned GPE?
> 
> Even if it is shared, the current code will not enable it if it sees
> ACPI_GPE_CAN_WAKE set.
> 
> We can change that logic, but that should be a separate patch IMO and
> this is not related to the problem at hand.

OK, I see.
We can enhance that on top of these fixes.

Thanks,
Lv