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authorLinus Torvalds <torvalds@linux-foundation.org>2012-02-04 15:21:39 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2012-02-04 15:21:39 -0800
commit23783f817bceedd6d4e549385e3f400ea64059e5 (patch)
treedb770bd3d7b9264e0f5ed614d9c570d729caf8de /kernel
parentd9142025f55973149a854c97e860fff61ed05b37 (diff)
parentd020283dc694c9ec31b410f522252f7a8397e67d (diff)
Merge tag 'pm-fixes-for-3.3-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Power management fixes for 3.3-rc3 Three power management regression fixes, one for a recent regression introcuded by the freezer changes during the 3.3 merge window and two for regressions in cpuidle (resulting from PM QoS changes) and in the hibernate user space interface, both introduced during the 3.2 development cycle. They include: * Two hibernate (s2disk) regression fixes from Srivatsa S. Bhat (for regressions introduced during the 3.3 merge window and during the 3.2 development cycle). * A cpuidle fix from Venki Pallipadi for a regression resulting from PM QoS changes during the 3.2 development cycle causing cpuidle to work incorrectly for CONFIG_PM unset. * tag 'pm-fixes-for-3.3-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: PM / QoS: CPU C-state breakage with PM Qos change PM / Freezer: Thaw only kernel threads if freezing of kernel threads fails PM / Hibernate: Thaw kernel threads in SNAPSHOT_CREATE_IMAGE ioctl path
Diffstat (limited to 'kernel')
-rw-r--r--kernel/power/power.h24
-rw-r--r--kernel/power/process.c7
-rw-r--r--kernel/power/user.c6
3 files changed, 31 insertions, 6 deletions
diff --git a/kernel/power/power.h b/kernel/power/power.h
index 0c4defe6d3b..21724eee520 100644
--- a/kernel/power/power.h
+++ b/kernel/power/power.h
@@ -231,8 +231,28 @@ extern int pm_test_level;
#ifdef CONFIG_SUSPEND_FREEZER
static inline int suspend_freeze_processes(void)
{
- int error = freeze_processes();
- return error ? : freeze_kernel_threads();
+ int error;
+
+ error = freeze_processes();
+
+ /*
+ * freeze_processes() automatically thaws every task if freezing
+ * fails. So we need not do anything extra upon error.
+ */
+ if (error)
+ goto Finish;
+
+ error = freeze_kernel_threads();
+
+ /*
+ * freeze_kernel_threads() thaws only kernel threads upon freezing
+ * failure. So we have to thaw the userspace tasks ourselves.
+ */
+ if (error)
+ thaw_processes();
+
+ Finish:
+ return error;
}
static inline void suspend_thaw_processes(void)
diff --git a/kernel/power/process.c b/kernel/power/process.c
index eeca00311f3..7e426459e60 100644
--- a/kernel/power/process.c
+++ b/kernel/power/process.c
@@ -143,7 +143,10 @@ int freeze_processes(void)
/**
* freeze_kernel_threads - Make freezable kernel threads go to the refrigerator.
*
- * On success, returns 0. On failure, -errno and system is fully thawed.
+ * On success, returns 0. On failure, -errno and only the kernel threads are
+ * thawed, so as to give a chance to the caller to do additional cleanups
+ * (if any) before thawing the userspace tasks. So, it is the responsibility
+ * of the caller to thaw the userspace tasks, when the time is right.
*/
int freeze_kernel_threads(void)
{
@@ -159,7 +162,7 @@ int freeze_kernel_threads(void)
BUG_ON(in_atomic());
if (error)
- thaw_processes();
+ thaw_kernel_threads();
return error;
}
diff --git a/kernel/power/user.c b/kernel/power/user.c
index e5a21a85730..3e100075b13 100644
--- a/kernel/power/user.c
+++ b/kernel/power/user.c
@@ -249,13 +249,15 @@ static long snapshot_ioctl(struct file *filp, unsigned int cmd,
}
pm_restore_gfp_mask();
error = hibernation_snapshot(data->platform_support);
- if (!error) {
+ if (error) {
+ thaw_kernel_threads();
+ } else {
error = put_user(in_suspend, (int __user *)arg);
if (!error && !freezer_test_done)
data->ready = 1;
if (freezer_test_done) {
freezer_test_done = false;
- thaw_processes();
+ thaw_kernel_threads();
}
}
break;