linux_dsm_epyc7002/drivers/base/power
Grygorii Strashko 0bf0ee8ef9 PM / wakeirq: Fix spurious wake-up events for dedicated wakeirqs
Dedicated wakeirq is a one time event to wake-up the system from
low-power state and then call pm_runtime_resume() on the device wired
with the dedicated wakeirq.

Sometimes dedicated wakeirqs can get deferred if they trigger after we
call disable_irq_nosync() in dev_pm_disable_wake_irq(). This can happen
if pm_runtime_get() is called around the same time a wakeirq fires.

If an interrupt fires after disable_irq_nosync(), by default it will get
tagged with IRQS_PENDING and will run later on when the interrupt is
enabled again.

Deferred wakeirqs usually just produce pointless wake-up events. But they
can also cause suspend to fail if the deferred wakeirq fires during
dpm_suspend_noirq() for example. So we really don't want to see the
deferred wakeirqs triggering after the device has resumed.

Let's fix the issue by setting IRQ_DISABLE_UNLAZY flag for the dedicated
wakeirqs. The other option would be to implement irq_disable() in the
dedicated wakeirq controller, but that's not a generic solution.

For reference below is what happens with a IRQ_TYPE_EDGE_BOTH IRQ
type wakeirq:

- resume by dedicated IRQ (EDGE_FALLING)
 - suspend_enter()
  ....
 - arch_suspend_enable_irqs()
   |- dedicated IRQ armed and fired
   |- irq_pm_check_wakeup()
      |- disarm, disable IRQ and mark as IRQS_PENDING
  ....
 - dpm_resume_noirq()
   |- resume_device_irqs()
      |- __enable_irq()
         |- check_irq_resend()
            |- handle_threaded_wake_irq()
 	       |- dedicated IRQ processed
   |- device_wakeup_disarm_wake_irqs()
      |- disable_irq_wake()
  ....
 !-> dedicated IRQ (EDGE_RISING)
     -| handle_edge_irq()
        |- IRQ disabled: mask_ack_irq and mark as IRQS_PENDING
  ....
- subsequent suspend
  ....
  |- dpm_suspend_noirq()
     |- device_wakeup_arm_wake_irqs()
        |- __enable_irq()
           |- check_irq_resend()
(a)           |- handle_threaded_wake_irq()
                 |- pm_wakeup_event() --> abort suspend
  ....
     |- suspend_device_irqs()
        |- suspend_device_irq()
           |-  dedicated IRQ armed
  ....
(b)  |- resend_irqs
        |- irq_pm_check_wakeup()
           |- IRQ armed -> abort suspend

because of pending IRQ System suspend can be aborted at points
(a)-not armed or (b)-armed.

Fixes: 4990d4fe32 (PM / Wakeirq: Add automated device wake IRQ handling)
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
[ tony@atomide.com: added a comment, updated the description ]
Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-02-13 22:29:30 +01:00
..
opp PM / OPP: Don't WARN on multiple calls to dev_pm_opp_set_regulators() 2016-12-06 02:28:00 +01:00
clock_ops.c PM / clk: Add support for adding a specific clock from device-tree 2016-06-28 00:42:10 +02:00
common.c PM: Avoid false-positive warnings in dev_pm_domain_set() 2016-02-03 19:10:37 +01:00
domain_governor.c PM / Domains: Rename stop_ok to suspend_ok for the genpd governor 2016-04-22 02:29:17 +02:00
domain.c PM / domains: Fix 'may be used uninitialized' build warning 2016-12-31 21:52:07 +01:00
generic_ops.c PM / PCI / ACPI: Kick devices that might have been reset by firmware 2015-10-14 02:17:34 +02:00
main.c ktime: Cleanup ktime_set() usage 2016-12-25 17:21:22 +01:00
Makefile PM / OPP: Move opp core to its own directory 2015-09-15 02:03:16 +02:00
power.h Driver core patches for 4.10-rc1 2016-12-13 11:42:18 -08:00
qos.c PM / QoS: Export dev_pm_qos_update_user_latency_tolerance 2016-11-30 22:34:24 +01:00
runtime.c PM / runtime: Avoid false-positive warnings from might_sleep_if() 2017-02-04 00:44:36 +01:00
sysfs.c PM / QoS: Improve sysfs pm_qos_latency_tolerance validation 2016-11-30 22:34:23 +01:00
trace.c timekeeping: Ignore the bogus sleep time if pm_trace is enabled 2016-11-29 18:02:58 +01:00
wakeirq.c PM / wakeirq: Fix spurious wake-up events for dedicated wakeirqs 2017-02-13 22:29:30 +01:00
wakeup.c ktime: Cleanup ktime_set() usage 2016-12-25 17:21:22 +01:00