On Monday, 18 of February 2008, Ingo Molnar wrote:
>
> * Pavel Machek <pavel@xxxxxx> wrote:
>
> > > Since this is increasingly unrelated to the "sleepy linux" concept
> > > (a version of what systems like OLPC, N700, and N800 are doing), I
> > > got rid of the "sleepy.c" file.
> >
> > What was the decision here? Ingo, did you merge this for 2.6.26, or
> > just for your test farm?
>
> it's working fine here, i've had it in my test-setup for a long time,
> and it triggers every now and then.
>
> We should merge the patch below. My only gripe that should be solved in
> an add-on patch is that right now it triggers with an about 1:100 chance
> in randconfig tests. The reason is the insane amount of user-selected
> options to get this vital functionality done. Could we _PLEASE_ get a
> prominent "new, cool RTC driver stuff" config option that just select's
> all the other options?
>
> > > drivers/char/Kconfig | 5 +
> > > drivers/rtc/Kconfig | 1
> > > kernel/power/Kconfig | 10 +++
> > > kernel/power/main.c | 163 +++++++++++++++++++++++++++++++++++++++++++++++++++
> > > 4 files changed, 178 insertions(+), 1 deletion(-)
>
> this cannot really go via x86.git.
In fact, it should go through the ACPI tree.
Thanks,
Rafael
> ------------>
> Subject: suspend/resume self-test
> From: David Brownell <david-b@xxxxxxxxxxx>
>
> Boot-time test for system suspend states (STR or standby). The generic
> RTC framework triggers wakeup alarms, used to exit those states.
>
> - Measures some aspects of suspend time; uses "jiffies". This
> should probably use a clocksource instead, since those often
> work properly even while IRQs are disabled.
>
> - Includes a command line parameter, which needs work yet ... it
> currently turns this test off, but it should also let the target
> state be specified (and maybe even default to "no test").
>
> Lightly tested on an ARM system, which reported that suspending devices
> took 7 msec and resuming them took 132 msec:
>
> * The PCMCIA stack misbehaved a bit. It didn't finish enumerating
> the card before it suspended, so the wakeup event came from the
> CF card IRQ not from the RTC!
>
> * The MMC stack misbehaved more seriously. It wants to remove devices
> during the suspend sequence (quite needlessly, on this hardware),
> which now makes Linux unhappy.
>
> Workaround in both cases was to take the memory card out before booting.
>
> Also includes some Kconfig tweaks to help reduce configuration bugs on
> x86, by avoiding the legacy RTC driver when the generic RTC framework
> is enabled ... those should become a separate patch.
>
> Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
> ---
> drivers/char/Kconfig | 5 +
> drivers/rtc/Kconfig | 1
> kernel/power/Kconfig | 10 +++
> kernel/power/main.c | 163 +++++++++++++++++++++++++++++++++++++++++++++++++++
> 4 files changed, 178 insertions(+), 1 deletion(-)
>
> Index: linux/drivers/char/Kconfig
> ===================================================================
> --- linux.orig/drivers/char/Kconfig
> +++ linux/drivers/char/Kconfig
> @@ -706,9 +706,12 @@ config NVRAM
> To compile this driver as a module, choose M here: the
> module will be called nvram.
>
> +comment "You are using the RTC framework, not the legacy CMOS RTC driver"
> + depends on RTC_DRV_CMOS
> +
> config RTC
> tristate "Enhanced Real Time Clock Support"
> - depends on !PPC && !PARISC && !IA64 && !M68K && !SPARC && !FRV && !ARM && !SUPERH && !S390
> + depends on !PPC && !PARISC && !IA64 && !M68K && !SPARC && !FRV && !ARM && !SUPERH && !S390 && !RTC_DRV_CMOS
> ---help---
> If you say Y here and create a character special file /dev/rtc with
> major number 10 and minor number 135 using mknod ("man mknod"), you
> Index: linux/drivers/rtc/Kconfig
> ===================================================================
> --- linux.orig/drivers/rtc/Kconfig
> +++ linux/drivers/rtc/Kconfig
> @@ -294,6 +294,7 @@ comment "Platform RTC drivers"
> config RTC_DRV_CMOS
> tristate "PC-style 'CMOS'"
> depends on X86 || ALPHA || ARM || M32R || ATARI || PPC || MIPS
> + default y if X86
> help
> Say "yes" here to get direct support for the real time clock
> found in every PC or ACPI-based system, and some other boards.
> Index: linux/kernel/power/Kconfig
> ===================================================================
> --- linux.orig/kernel/power/Kconfig
> +++ linux/kernel/power/Kconfig
> @@ -104,6 +104,16 @@ config SUSPEND
> powered and thus its contents are preserved, such as the
> suspend-to-RAM state (e.g. the ACPI S3 state).
>
> +config PM_TEST_SUSPEND
> + bool "Test suspend/resume and wakealarm during bootup"
> + depends on SUSPEND && PM_DEBUG && RTC_LIB=y
> + ---help---
> + This option will suspend your machine during bootup, and make
> + it wake up a few seconds later using the RTC's wakeup alarm.
> +
> + You probably want to have your system's RTC driver statically
> + linked, ensuring that it's available when this test runs.
> +
> config SUSPEND_FREEZER
> bool "Enable freezer for suspend to RAM/standby" \
> if ARCH_WANTS_FREEZER_CONTROL || BROKEN
> Index: linux/kernel/power/main.c
> ===================================================================
> --- linux.orig/kernel/power/main.c
> +++ linux/kernel/power/main.c
> @@ -132,6 +132,52 @@ static inline int suspend_test(int level
>
> #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((nj >= 0) ? nj : -nj);
> + pr_info("PM: %s took %d.%03d seconds\n", label,
> + msec / 1000, msec % 1000);
> + WARN_ON_ONCE(msec > ((TEST_SUSPEND_SECONDS+5) * 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)
>
> @@ -264,11 +310,14 @@ int suspend_devices_and_enter(suspend_st
> 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 Resume_console;
> }
> + suspend_test_finish("suspend devices");
>
> if (suspend_test(TEST_DEVICES))
> goto Resume_devices;
> @@ -291,7 +340,9 @@ int suspend_devices_and_enter(suspend_st
> if (suspend_ops->finish)
> suspend_ops->finish();
> Resume_devices:
> + suspend_test_start();
> device_resume();
> + suspend_test_finish("resume devices");
> Resume_console:
> resume_console();
> Close:
> @@ -515,3 +566,115 @@ 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 with wakeup alarms are the the most common mechanism
> + * that's self-contained.
> + */
> +
> +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;
> +}
> +
> +/*
> + * We normally test Suspend-to-RAM, with standby as a backup when
> + * the system doesn't support that state. But we also need to be
> + * able to disable the powerup test, and tell it to ignore STR since
> + * the RTC may not work then.
> + */
> +static suspend_state_t test_state __initdata = PM_SUSPEND_MEM;
> +
> +static int __init setup_test_suspend(char *value)
> +{
> + /* FIXME accept "standby", etc */
> + test_state = PM_SUSPEND_ON;
> + 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;
> +
> + class_find_device(rtc_class, &pony, has_wakealarm);
> + if (pony)
> + rtc = rtc_class_open(pony);
> +
> + if (rtc) {
> + if (test_state != PM_SUSPEND_ON)
> + test_wakealarm(rtc, test_state);
> + rtc_class_close(rtc);
> + } else
> + printk(warn_no_rtc);
> +
> + return 0;
> +}
> +late_initcall(test_suspend);
> +
> +#endif /* CONFIG_PM_TEST_SUSPEND */
>
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