PM: Warn if interrupts are enabled during suspend-resume of sysdevs

Sysdevs have to be suspended and resumed with interrupts disabled and
things usually break in a way that's difficult to debug if one of
sysdev drivers enables interrupts by mistake during suspend or
resume.  Add extra checks that will generate warnings in such cases.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

diff --git a/drivers/base/sys.c b/drivers/base/sys.c
index 3236b43..9742a78 100644 (file)
--- a/drivers/base/sys.c
+++ b/drivers/base/sys.c
@@ -343,11 +343,15 @@ static void __sysdev_resume(struct sys_device *dev)
        /* First, call the class-specific one */
        if (cls->resume)
                cls->resume(dev);
+       WARN_ONCE(!irqs_disabled(),
+               "Interrupts enabled after %pF\n", cls->resume);
 
        /* Call auxillary drivers next. */
        list_for_each_entry(drv, &cls->drivers, entry) {
                if (drv->resume)
                        drv->resume(dev);
+               WARN_ONCE(!irqs_disabled(),
+                       "Interrupts enabled after %pF\n", drv->resume);
        }
 }
 
@@ -377,6 +381,9 @@ int sysdev_suspend(pm_message_t state)
        if (ret)
                return ret;
 
+       WARN_ONCE(!irqs_disabled(),
+               "Interrupts enabled while suspending system devices\n");
+
        pr_debug("Suspending System Devices\n");
 
        list_for_each_entry_reverse(cls, &system_kset->list, kset.kobj.entry) {
@@ -393,6 +400,9 @@ int sysdev_suspend(pm_message_t state)
                                        if (ret)
                                                goto aux_driver;
                                }
+                               WARN_ONCE(!irqs_disabled(),
+                                       "Interrupts enabled after %pF\n",
+                                       drv->suspend);
                        }
 
                        /* Now call the generic one */
@@ -400,6 +410,9 @@ int sysdev_suspend(pm_message_t state)
                                ret = cls->suspend(sysdev, state);
                                if (ret)
                                        goto cls_driver;
+                               WARN_ONCE(!irqs_disabled(),
+                                       "Interrupts enabled after %pF\n",
+                                       cls->suspend);
                        }
                }
        }
@@ -452,6 +465,9 @@ int sysdev_resume(void)
 {
        struct sysdev_class *cls;
 
+       WARN_ONCE(!irqs_disabled(),
+               "Interrupts enabled while resuming system devices\n");
+
        pr_debug("Resuming System Devices\n");
 
        list_for_each_entry(cls, &system_kset->list, kset.kobj.entry) {