Merge branch 'semaphore' of git://git.kernel.org/pub/scm/linux/kernel/git/willy/misc
[pandora-kernel.git] / kernel / power / main.c
index 3398f46..95bff23 100644 (file)
@@ -132,6 +132,61 @@ static inline int suspend_test(int level) { return 0; }
 
 #ifdef CONFIG_SUSPEND
 
+#ifdef CONFIG_PM_TEST_SUSPEND
+
+/*
+ * We test the system suspend code by setting an RTC wakealarm a short
+ * time in the future, then suspending.  Suspending the devices won't
+ * normally take long ... some systems only need a few milliseconds.
+ *
+ * The time it takes is system-specific though, so when we test this
+ * during system bootup we allow a LOT of time.
+ */
+#define TEST_SUSPEND_SECONDS   5
+
+static unsigned long suspend_test_start_time;
+
+static void suspend_test_start(void)
+{
+       /* FIXME Use better timebase than "jiffies", ideally a clocksource.
+        * What we want is a hardware counter that will work correctly even
+        * during the irqs-are-off stages of the suspend/resume cycle...
+        */
+       suspend_test_start_time = jiffies;
+}
+
+static void suspend_test_finish(const char *label)
+{
+       long nj = jiffies - suspend_test_start_time;
+       unsigned msec;
+
+       msec = jiffies_to_msecs(abs(nj));
+       pr_info("PM: %s took %d.%03d seconds\n", label,
+                       msec / 1000, msec % 1000);
+
+       /* Warning on suspend means the RTC alarm period needs to be
+        * larger -- the system was sooo slooowwww to suspend that the
+        * alarm (should have) fired before the system went to sleep!
+        *
+        * Warning on either suspend or resume also means the system
+        * has some performance issues.  The stack dump of a WARN_ON
+        * is more likely to get the right attention than a printk...
+        */
+       WARN_ON(msec > (TEST_SUSPEND_SECONDS * 1000));
+}
+
+#else
+
+static void suspend_test_start(void)
+{
+}
+
+static void suspend_test_finish(const char *label)
+{
+}
+
+#endif
+
 /* This is just an arbitrary number */
 #define FREE_PAGE_NUMBER (100)
 
@@ -266,12 +321,13 @@ int suspend_devices_and_enter(suspend_state_t state)
                        goto Close;
        }
        suspend_console();
+       suspend_test_start();
        error = device_suspend(PMSG_SUSPEND);
        if (error) {
                printk(KERN_ERR "PM: Some devices failed to suspend\n");
                goto Recover_platform;
        }
-
+       suspend_test_finish("suspend devices");
        if (suspend_test(TEST_DEVICES))
                goto Recover_platform;
 
@@ -293,7 +349,9 @@ int suspend_devices_and_enter(suspend_state_t state)
        if (suspend_ops->finish)
                suspend_ops->finish();
  Resume_devices:
+       suspend_test_start();
        device_resume(PMSG_RESUME);
+       suspend_test_finish("resume devices");
        resume_console();
  Close:
        if (suspend_ops->end)
@@ -521,3 +579,137 @@ static int __init pm_init(void)
 }
 
 core_initcall(pm_init);
+
+
+#ifdef CONFIG_PM_TEST_SUSPEND
+
+#include <linux/rtc.h>
+
+/*
+ * To test system suspend, we need a hands-off mechanism to resume the
+ * system.  RTCs wake alarms are a common self-contained mechanism.
+ */
+
+static void __init test_wakealarm(struct rtc_device *rtc, suspend_state_t state)
+{
+       static char err_readtime[] __initdata =
+               KERN_ERR "PM: can't read %s time, err %d\n";
+       static char err_wakealarm [] __initdata =
+               KERN_ERR "PM: can't set %s wakealarm, err %d\n";
+       static char err_suspend[] __initdata =
+               KERN_ERR "PM: suspend test failed, error %d\n";
+       static char info_test[] __initdata =
+               KERN_INFO "PM: test RTC wakeup from '%s' suspend\n";
+
+       unsigned long           now;
+       struct rtc_wkalrm       alm;
+       int                     status;
+
+       /* this may fail if the RTC hasn't been initialized */
+       status = rtc_read_time(rtc, &alm.time);
+       if (status < 0) {
+               printk(err_readtime, rtc->dev.bus_id, status);
+               return;
+       }
+       rtc_tm_to_time(&alm.time, &now);
+
+       memset(&alm, 0, sizeof alm);
+       rtc_time_to_tm(now + TEST_SUSPEND_SECONDS, &alm.time);
+       alm.enabled = true;
+
+       status = rtc_set_alarm(rtc, &alm);
+       if (status < 0) {
+               printk(err_wakealarm, rtc->dev.bus_id, status);
+               return;
+       }
+
+       if (state == PM_SUSPEND_MEM) {
+               printk(info_test, pm_states[state]);
+               status = pm_suspend(state);
+               if (status == -ENODEV)
+                       state = PM_SUSPEND_STANDBY;
+       }
+       if (state == PM_SUSPEND_STANDBY) {
+               printk(info_test, pm_states[state]);
+               status = pm_suspend(state);
+       }
+       if (status < 0)
+               printk(err_suspend, status);
+}
+
+static int __init has_wakealarm(struct device *dev, void *name_ptr)
+{
+       struct rtc_device *candidate = to_rtc_device(dev);
+
+       if (!candidate->ops->set_alarm)
+               return 0;
+       if (!device_may_wakeup(candidate->dev.parent))
+               return 0;
+
+       *(char **)name_ptr = dev->bus_id;
+       return 1;
+}
+
+/*
+ * Kernel options like "test_suspend=mem" force suspend/resume sanity tests
+ * at startup time.  They're normally disabled, for faster boot and because
+ * we can't know which states really work on this particular system.
+ */
+static suspend_state_t test_state __initdata = PM_SUSPEND_ON;
+
+static char warn_bad_state[] __initdata =
+       KERN_WARNING "PM: can't test '%s' suspend state\n";
+
+static int __init setup_test_suspend(char *value)
+{
+       unsigned i;
+
+       /* "=mem" ==> "mem" */
+       value++;
+       for (i = 0; i < PM_SUSPEND_MAX; i++) {
+               if (!pm_states[i])
+                       continue;
+               if (strcmp(pm_states[i], value) != 0)
+                       continue;
+               test_state = (__force suspend_state_t) i;
+               return 0;
+       }
+       printk(warn_bad_state, value);
+       return 0;
+}
+__setup("test_suspend", setup_test_suspend);
+
+static int __init test_suspend(void)
+{
+       static char             warn_no_rtc[] __initdata =
+               KERN_WARNING "PM: no wakealarm-capable RTC driver is ready\n";
+
+       char                    *pony = NULL;
+       struct rtc_device       *rtc = NULL;
+
+       /* PM is initialized by now; is that state testable? */
+       if (test_state == PM_SUSPEND_ON)
+               goto done;
+       if (!valid_state(test_state)) {
+               printk(warn_bad_state, pm_states[test_state]);
+               goto done;
+       }
+
+       /* RTCs have initialized by now too ... can we use one? */
+       class_find_device(rtc_class, NULL, &pony, has_wakealarm);
+       if (pony)
+               rtc = rtc_class_open(pony);
+       if (!rtc) {
+               printk(warn_no_rtc);
+               goto done;
+       }
+
+       /* go for it */
+       test_wakealarm(rtc, test_state);
+       rtc_class_close(rtc);
+done:
+       return 0;
+}
+late_initcall(test_suspend);
+
+#endif /* CONFIG_PM_TEST_SUSPEND */