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authorRafael J. Wysocki <rjw@sisk.pl>2009-04-19 20:08:42 +0200
committerRafael J. Wysocki <rjw@sisk.pl>2009-04-19 20:08:42 +0200
commit6a7c7eaf71b636f197d73b381a2ab729ebdcfb2e (patch)
tree73c642bff623c2f1a87f6c353b21e3484bd9e899
parentff54250a0ebab7f90a5f848a0ba63f999830c872 (diff)
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PM/Suspend: Introduce two new platform callbacks to avoid breakage
Commit 900af0d973856d6feb6fc088c2d0d3fde57707d3 (PM: Change suspend code ordering) changed the ordering of suspend code in such a way that the platform .prepare() callback is now executed after the device drivers' late suspend callbacks have run. Unfortunately, this turns out to break ARM platforms that need to talk via I2C to power control devices during the .prepare() callback. For this reason introduce two new platform suspend callbacks, .prepare_late() and .wake(), that will be called just prior to disabling non-boot CPUs and right after bringing them back on line, respectively, and use them instead of .prepare() and .finish() for ACPI suspend. Make the PM core execute the .prepare() and .finish() platform suspend callbacks where they were executed previously (that is, right after calling the regular suspend methods provided by device drivers and right before executing their regular resume methods, respectively). It is not necessary to make analogous changes to the hibernation code and data structures at the moment, because they are only used by ACPI platforms. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Reported-by: Russell King <rmk+kernel@arm.linux.org.uk> Acked-by: Len Brown <len.brown@intel.com>
-rw-r--r--drivers/acpi/sleep.c8
-rw-r--r--include/linux/suspend.h36
-rw-r--r--kernel/power/main.c24
3 files changed, 47 insertions, 21 deletions
diff --git a/drivers/acpi/sleep.c b/drivers/acpi/sleep.c
index 779e4e500df..d060e6fd7fd 100644
--- a/drivers/acpi/sleep.c
+++ b/drivers/acpi/sleep.c
@@ -300,9 +300,9 @@ static int acpi_suspend_state_valid(suspend_state_t pm_state)
static struct platform_suspend_ops acpi_suspend_ops = {
.valid = acpi_suspend_state_valid,
.begin = acpi_suspend_begin,
- .prepare = acpi_pm_prepare,
+ .prepare_late = acpi_pm_prepare,
.enter = acpi_suspend_enter,
- .finish = acpi_pm_finish,
+ .wake = acpi_pm_finish,
.end = acpi_pm_end,
};
@@ -328,9 +328,9 @@ static int acpi_suspend_begin_old(suspend_state_t pm_state)
static struct platform_suspend_ops acpi_suspend_ops_old = {
.valid = acpi_suspend_state_valid,
.begin = acpi_suspend_begin_old,
- .prepare = acpi_pm_disable_gpes,
+ .prepare_late = acpi_pm_disable_gpes,
.enter = acpi_suspend_enter,
- .finish = acpi_pm_finish,
+ .wake = acpi_pm_finish,
.end = acpi_pm_end,
.recover = acpi_pm_finish,
};
diff --git a/include/linux/suspend.h b/include/linux/suspend.h
index 3e3a4364cbf..795032edfc4 100644
--- a/include/linux/suspend.h
+++ b/include/linux/suspend.h
@@ -58,10 +58,17 @@ typedef int __bitwise suspend_state_t;
* by @begin().
* @prepare() is called right after devices have been suspended (ie. the
* appropriate .suspend() method has been executed for each device) and
- * before the nonboot CPUs are disabled (it is executed with IRQs enabled).
- * This callback is optional. It returns 0 on success or a negative
- * error code otherwise, in which case the system cannot enter the desired
- * sleep state (@enter() and @finish() will not be called in that case).
+ * before device drivers' late suspend callbacks are executed. It returns
+ * 0 on success or a negative error code otherwise, in which case the
+ * system cannot enter the desired sleep state (@prepare_late(), @enter(),
+ * @wake(), and @finish() will not be called in that case).
+ *
+ * @prepare_late: Finish preparing the platform for entering the system sleep
+ * state indicated by @begin().
+ * @prepare_late is called before disabling nonboot CPUs and after
+ * device drivers' late suspend callbacks have been executed. It returns
+ * 0 on success or a negative error code otherwise, in which case the
+ * system cannot enter the desired sleep state (@enter() and @wake()).
*
* @enter: Enter the system sleep state indicated by @begin() or represented by
* the argument if @begin() is not implemented.
@@ -69,19 +76,26 @@ typedef int __bitwise suspend_state_t;
* error code otherwise, in which case the system cannot enter the desired
* sleep state.
*
- * @finish: Called when the system has just left a sleep state, right after
- * the nonboot CPUs have been enabled and before devices are resumed (it is
- * executed with IRQs enabled).
+ * @wake: Called when the system has just left a sleep state, right after
+ * the nonboot CPUs have been enabled and before device drivers' early
+ * resume callbacks are executed.
+ * This callback is optional, but should be implemented by the platforms
+ * that implement @prepare_late(). If implemented, it is always called
+ * after @enter(), even if @enter() fails.
+ *
+ * @finish: Finish wake-up of the platform.
+ * @finish is called right prior to calling device drivers' regular suspend
+ * callbacks.
* This callback is optional, but should be implemented by the platforms
* that implement @prepare(). If implemented, it is always called after
- * @enter() (even if @enter() fails).
+ * @enter() and @wake(), if implemented, even if any of them fails.
*
* @end: Called by the PM core right after resuming devices, to indicate to
* the platform that the system has returned to the working state or
* the transition to the sleep state has been aborted.
* This callback is optional, but should be implemented by the platforms
- * that implement @begin(), but platforms implementing @begin() should
- * also provide a @end() which cleans up transitions aborted before
+ * that implement @begin(). Accordingly, platforms implementing @begin()
+ * should also provide a @end() which cleans up transitions aborted before
* @enter().
*
* @recover: Recover the platform from a suspend failure.
@@ -93,7 +107,9 @@ struct platform_suspend_ops {
int (*valid)(suspend_state_t state);
int (*begin)(suspend_state_t state);
int (*prepare)(void);
+ int (*prepare_late)(void);
int (*enter)(suspend_state_t state);
+ void (*wake)(void);
void (*finish)(void);
void (*end)(void);
void (*recover)(void);
diff --git a/kernel/power/main.c b/kernel/power/main.c
index f172f41858b..f99ed6a75ea 100644
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -291,20 +291,26 @@ static int suspend_enter(suspend_state_t state)
device_pm_lock();
+ if (suspend_ops->prepare) {
+ error = suspend_ops->prepare();
+ if (error)
+ goto Done;
+ }
+
error = device_power_down(PMSG_SUSPEND);
if (error) {
printk(KERN_ERR "PM: Some devices failed to power down\n");
- goto Done;
+ goto Platfrom_finish;
}
- if (suspend_ops->prepare) {
- error = suspend_ops->prepare();
+ if (suspend_ops->prepare_late) {
+ error = suspend_ops->prepare_late();
if (error)
goto Power_up_devices;
}
if (suspend_test(TEST_PLATFORM))
- goto Platfrom_finish;
+ goto Platform_wake;
error = disable_nonboot_cpus();
if (error || suspend_test(TEST_CPUS))
@@ -326,13 +332,17 @@ static int suspend_enter(suspend_state_t state)
Enable_cpus:
enable_nonboot_cpus();
- Platfrom_finish:
- if (suspend_ops->finish)
- suspend_ops->finish();
+ Platform_wake:
+ if (suspend_ops->wake)
+ suspend_ops->wake();
Power_up_devices:
device_power_up(PMSG_RESUME);
+ Platfrom_finish:
+ if (suspend_ops->finish)
+ suspend_ops->finish();
+
Done:
device_pm_unlock();