PM: Rework handling of interrupts during suspend-resume

Use the functions introduced in by the previous patch,
suspend_device_irqs(), resume_device_irqs() and check_wakeup_irqs(),
to rework the handling of interrupts during suspend (hibernation) and
resume.  Namely, interrupts will only be disabled on the CPU right
before suspending sysdevs, while device drivers will be prevented
from receiving interrupts, with the help of the new helper function,
before their "late" suspend callbacks run (and analogously during
resume).

In addition, since the device interrups are now disabled before the
CPU has turned all interrupts off and the CPU will ACK the interrupts
setting the IRQ_PENDING bit for them, check in sysdev_suspend() if
any wake-up interrupts are pending and abort suspend if that's the
case.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Ingo Molnar <mingo@elte.hu>

3 files changed, 44 insertions, 20 deletions

diff --git a/kernel/kexec.c b/kernel/kexec.c
index c7fd6692939d..dade9af6bf21 100644
--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -1454,7 +1454,6 @@ int kernel_kexec(void)
                 if (error)
                         goto Resume_devices;
                 device_pm_lock();
-                local_irq_disable();
                 /* At this point, device_suspend() has been called,
                  * but *not* device_power_down(). We *must*
                  * device_power_down() now.  Otherwise, drivers for
@@ -1464,8 +1463,9 @@ int kernel_kexec(void)
                  */
                 error = device_power_down(PMSG_FREEZE);
                 if (error)
-                        goto Enable_irqs;
+                        goto Unlock_pm;
 
+                local_irq_disable();
                 /* Suspend system devices */
                 error = sysdev_suspend(PMSG_FREEZE);
                 if (error)
@@ -1484,9 +1484,9 @@ int kernel_kexec(void)
         if (kexec_image->preserve_context) {
                 sysdev_resume();
  Power_up_devices:
-                device_power_up(PMSG_RESTORE);
- Enable_irqs:
                 local_irq_enable();
+                device_power_up(PMSG_RESTORE);
+ Unlock_pm:
                 device_pm_unlock();
                 enable_nonboot_cpus();
  Resume_devices:
diff --git a/kernel/power/disk.c b/kernel/power/disk.c
index 4a4a206b1979..320bb0949bdf 100644
--- a/kernel/power/disk.c
+++ b/kernel/power/disk.c
@@ -214,7 +214,7 @@ static int create_image(int platform_mode)
                 return error;
 
         device_pm_lock();
-        local_irq_disable();
+
         /* At this point, device_suspend() has been called, but *not*
          * device_power_down(). We *must* call device_power_down() now.
          * Otherwise, drivers for some devices (e.g. interrupt controllers)
@@ -225,8 +225,11 @@ static int create_image(int platform_mode)
         if (error) {
                 printk(KERN_ERR "PM: Some devices failed to power down, "
                         "aborting hibernation\n");
-                goto Enable_irqs;
+                goto Unlock;
         }
+
+        local_irq_disable();
+
         sysdev_suspend(PMSG_FREEZE);
         if (error) {
                 printk(KERN_ERR "PM: Some devices failed to power down, "
@@ -252,12 +255,16 @@ static int create_image(int platform_mode)
         /* NOTE:  device_power_up() is just a resume() for devices
          * that suspended with irqs off ... no overall powerup.
          */
+
  Power_up_devices:
+        local_irq_enable();
+
         device_power_up(in_suspend ?
                 (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
- Enable_irqs:
-        local_irq_enable();
+
+ Unlock:
         device_pm_unlock();
+
         return error;
 }
 
@@ -336,13 +343,16 @@ static int resume_target_kernel(void)
         int error;
 
         device_pm_lock();
-        local_irq_disable();
+
         error = device_power_down(PMSG_QUIESCE);
         if (error) {
                 printk(KERN_ERR "PM: Some devices failed to power down, "
                         "aborting resume\n");
-                goto Enable_irqs;
+                goto Unlock;
         }
+
+        local_irq_disable();
+
         sysdev_suspend(PMSG_QUIESCE);
         /* We'll ignore saved state, but this gets preempt count (etc) right */
         save_processor_state();
@@ -366,11 +376,16 @@ static int resume_target_kernel(void)
         swsusp_free();
         restore_processor_state();
         touch_softlockup_watchdog();
+
         sysdev_resume();
-        device_power_up(PMSG_RECOVER);
- Enable_irqs:
+
         local_irq_enable();
+
+        device_power_up(PMSG_RECOVER);
+
+ Unlock:
         device_pm_unlock();
+
         return error;
 }
 
@@ -447,15 +462,16 @@ int hibernation_platform_enter(void)
                 goto Finish;
 
         device_pm_lock();
-        local_irq_disable();
+
         error = device_power_down(PMSG_HIBERNATE);
         if (!error) {
+                local_irq_disable();
                 sysdev_suspend(PMSG_HIBERNATE);
                 hibernation_ops->enter();
                 /* We should never get here */
                 while (1);
         }
-        local_irq_enable();
+
         device_pm_unlock();
 
         /*
@@ -464,12 +480,15 @@ int hibernation_platform_enter(void)
          */
  Finish:
         hibernation_ops->finish();
+
  Resume_devices:
         entering_platform_hibernation = false;
         device_resume(PMSG_RESTORE);
         resume_console();
+
  Close:
         hibernation_ops->end();
+
         return error;
 }
 
diff --git a/kernel/power/main.c b/kernel/power/main.c
index c9632f841f64..f0a466736c01 100644
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -287,17 +287,19 @@ void __attribute__ ((weak)) arch_suspend_enable_irqs(void)
  */
 static int suspend_enter(suspend_state_t state)
 {
-        int error = 0;
+        int error;
 
         device_pm_lock();
-        arch_suspend_disable_irqs();
-        BUG_ON(!irqs_disabled());
 
-        if ((error = device_power_down(PMSG_SUSPEND))) {
+        error = device_power_down(PMSG_SUSPEND);
+        if (error) {
                 printk(KERN_ERR "PM: Some devices failed to power down\n");
                 goto Done;
         }
 
+        arch_suspend_disable_irqs();
+        BUG_ON(!irqs_disabled());
+
         error = sysdev_suspend(PMSG_SUSPEND);
         if (!error) {
                 if (!suspend_test(TEST_CORE))
@@ -305,11 +307,14 @@ static int suspend_enter(suspend_state_t state)
                 sysdev_resume();
         }
 
-        device_power_up(PMSG_RESUME);
- Done:
         arch_suspend_enable_irqs();
         BUG_ON(irqs_disabled());
+
+        device_power_up(PMSG_RESUME);
+
+ Done:
         device_pm_unlock();
+
         return error;
 }