Re: [PATCH] [v2] ACPI / PM: Fix incorrect wakeup irq setting before suspend-to-idle

[Rafael J. Wysocki]

On Sunday, September 27, 2015 09:23:10 AM Chen Yu wrote:
> For ACPI compatible system, SCI(ACPI System Control
> Interrupt) is used to wake system up from suspend-to-idle.
> Once CPU is woken up by SCI, interrupt handler will
> firstly checks if current interrupt is legal to wake up
> the whole system, thus irq_pm_check_wakeup is invoked
> to validate the irq number. However, before suspend-to-idle,
> acpi_gbl_FADT.sci_interrupt is marked rather than actual
> irq number in acpi_freeze_prepare, this might lead to unable
> to wake up the system.
> 
> This patch fixes this problem by marking the irq number
> return by acpi_gsi_to_irq as IRQD_WAKEUP_STATE, rather than
> marking the acpi_gbl_FADT.sci_interrupt. Meanwhile this patch
> fixes the same problems inside acpi_os_remove_interrupt_handler
> and acpi_os_wait_events_complete respectively.
> 
> Signed-off-by: Chen Yu <yu.c.chen@xxxxxxxxx>
> ---
> v2:
>  - 1.Define a global acpi_inuse_irq variable, store irq in it
>    and access it directly from acpi_freeze_prepare(), and it
>    doesn't have to depend on CONFIG_SUSPEND as it is just the
>    IRQ number actually used by ACPI.
>    2.Also fix the same problems inside acpi_os_remove_interrupt_handler,
>    acpi_os_wait_events_complete.
> ---
>  drivers/acpi/osl.c   |  9 ++++++++-
>  drivers/acpi/sleep.c | 10 ++++++++--
>  include/linux/acpi.h |  3 +++
>  3 files changed, 19 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c
> index 739a4a6..97507fc 100644
> --- a/drivers/acpi/osl.c
> +++ b/drivers/acpi/osl.c
> @@ -81,6 +81,7 @@ static struct workqueue_struct *kacpid_wq;
>  static struct workqueue_struct *kacpi_notify_wq;
>  static struct workqueue_struct *kacpi_hotplug_wq;
>  static bool acpi_os_initialized;
> +unsigned int acpi_inuse_irq = INVALID_ACPI_IRQ;

What about calling it acpi_sci_irq instead?

>  
>  /*
>   * This list of permanent mappings is for memory that may be accessed from
> @@ -856,6 +857,7 @@ acpi_os_install_interrupt_handler(u32 gsi, acpi_osd_handler handler,
>  		acpi_irq_handler = NULL;
>  		return AE_NOT_ACQUIRED;
>  	}
> +	acpi_inuse_irq = irq;
>  
>  	return AE_OK;
>  }
> @@ -865,6 +867,9 @@ acpi_status acpi_os_remove_interrupt_handler(u32 irq, acpi_osd_handler handler)
>  	if (irq != acpi_gbl_FADT.sci_interrupt)
>  		return AE_BAD_PARAMETER;
>  
> +	if (!IS_INVALID_ACPI_IRQ(acpi_inuse_irq))
> +		irq = acpi_inuse_irq;

I'd think that we should return from here if acpi_inuse_irq is invalid?

It surely can't be invalid if acpi_os_install_interrupt_handler() has succeeded,
right?

> +
>  	free_irq(irq, acpi_irq);
>  	acpi_irq_handler = NULL;
>  
> @@ -1176,12 +1181,14 @@ EXPORT_SYMBOL(acpi_os_execute);
>  
>  void acpi_os_wait_events_complete(void)
>  {
> +	unsigned int irq = IS_INVALID_ACPI_IRQ(acpi_inuse_irq) ?
> +		acpi_gbl_FADT.sci_interrupt : acpi_inuse_irq;

That, again.  If acpi_inuse_irq is invalid, acpi_os_install_interrupt_handler()
has failed, so we have nothing to synchronize here, or am I missing anything?

>  	/*
>  	 * Make sure the GPE handler or the fixed event handler is not used
>  	 * on another CPU after removal.
>  	 */
>  	if (acpi_irq_handler)
> -		synchronize_hardirq(acpi_gbl_FADT.sci_interrupt);
> +		synchronize_hardirq(irq);
>  	flush_workqueue(kacpid_wq);
>  	flush_workqueue(kacpi_notify_wq);
>  }
> diff --git a/drivers/acpi/sleep.c b/drivers/acpi/sleep.c
> index 2f0d4db..a7a467b 100644
> --- a/drivers/acpi/sleep.c
> +++ b/drivers/acpi/sleep.c
> @@ -629,17 +629,23 @@ static int acpi_freeze_begin(void)
>  
>  static int acpi_freeze_prepare(void)
>  {
> +	unsigned int irq = IS_INVALID_ACPI_IRQ(acpi_inuse_irq) ?
> +		acpi_gbl_FADT.sci_interrupt : acpi_inuse_irq;

Same comment as above.

Plus, you seem to be duplicating code from acpi_os_wait_events_complete()
here, so what about putting it into a separate routine (maybe static inline)?

> +
>  	acpi_enable_wakeup_devices(ACPI_STATE_S0);
>  	acpi_enable_all_wakeup_gpes();
>  	acpi_os_wait_events_complete();
> -	enable_irq_wake(acpi_gbl_FADT.sci_interrupt);
> +	enable_irq_wake(irq);
>  	return 0;
>  }
>  
>  static void acpi_freeze_restore(void)
>  {
> +	unsigned int irq = IS_INVALID_ACPI_IRQ(acpi_inuse_irq) ?
> +		acpi_gbl_FADT.sci_interrupt : acpi_inuse_irq;
> +

Ditto.

>  	acpi_disable_wakeup_devices(ACPI_STATE_S0);
> -	disable_irq_wake(acpi_gbl_FADT.sci_interrupt);
> +	disable_irq_wake(irq);
>  	acpi_enable_all_runtime_gpes();
>  }
>  
> diff --git a/include/linux/acpi.h b/include/linux/acpi.h
> index 7235c48..df8ed19 100644
> --- a/include/linux/acpi.h
> +++ b/include/linux/acpi.h
> @@ -193,6 +193,9 @@ int acpi_ioapic_registered(acpi_handle handle, u32 gsi_base);
>  void acpi_irq_stats_init(void);
>  extern u32 acpi_irq_handled;
>  extern u32 acpi_irq_not_handled;
> +extern unsigned int acpi_inuse_irq;
> +#define INVALID_ACPI_IRQ  ((unsigned)-1)
> +#define IS_INVALID_ACPI_IRQ(x) unlikely((x) == INVALID_ACPI_IRQ)
>  
>  extern int sbf_port;
>  extern unsigned long acpi_realmode_flags;

Thanks,
Rafael

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