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authorRafael J. Wysocki <rjw@sisk.pl>2008-10-15 22:01:21 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-10-16 11:21:29 -0700
commit1bfcf1304ea79c46efc3724e548b13b4b442b418 (patch)
tree5adbf95b25d1d9e86fc0e5d0784550ccb9bf5be9 /kernel/power
parent574f34cee2b6574d43bf4506f771c1cec6a5d391 (diff)
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pm: rework disabling of user mode helpers during suspend/hibernation
We currently use a PM notifier to disable user mode helpers before suspend and hibernation and to re-enable them during resume. However, this is not an ideal solution, because if any drivers want to upload firmware into memory before suspend, they have to use a PM notifier for this purpose and there is no guarantee that the ordering of PM notifiers will be as expected (ie. the notifier that disables user mode helpers has to be run after the driver's notifier used for uploading the firmware). For this reason, it seems better to move the disabling and enabling of user mode helpers to separate functions that will be called by the PM core as necessary. [akpm@linux-foundation.org: remove unneeded ifdefs] Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Cc: Alan Stern <stern@rowland.harvard.edu> Acked-by: Pavel Machek <pavel@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/power')
-rw-r--r--kernel/power/disk.c11
-rw-r--r--kernel/power/main.c7
-rw-r--r--kernel/power/user.c10
3 files changed, 27 insertions, 1 deletions
diff --git a/kernel/power/disk.c b/kernel/power/disk.c
index bbd85c60f741..331f9836383f 100644
--- a/kernel/power/disk.c
+++ b/kernel/power/disk.c
@@ -14,6 +14,7 @@
#include <linux/reboot.h>
#include <linux/string.h>
#include <linux/device.h>
+#include <linux/kmod.h>
#include <linux/delay.h>
#include <linux/fs.h>
#include <linux/mount.h>
@@ -520,6 +521,10 @@ int hibernate(void)
if (error)
goto Exit;
+ error = usermodehelper_disable();
+ if (error)
+ goto Exit;
+
/* Allocate memory management structures */
error = create_basic_memory_bitmaps();
if (error)
@@ -558,6 +563,7 @@ int hibernate(void)
thaw_processes();
Finish:
free_basic_memory_bitmaps();
+ usermodehelper_enable();
Exit:
pm_notifier_call_chain(PM_POST_HIBERNATION);
pm_restore_console();
@@ -634,6 +640,10 @@ static int software_resume(void)
if (error)
goto Finish;
+ error = usermodehelper_disable();
+ if (error)
+ goto Finish;
+
error = create_basic_memory_bitmaps();
if (error)
goto Finish;
@@ -656,6 +666,7 @@ static int software_resume(void)
thaw_processes();
Done:
free_basic_memory_bitmaps();
+ usermodehelper_enable();
Finish:
pm_notifier_call_chain(PM_POST_RESTORE);
pm_restore_console();
diff --git a/kernel/power/main.c b/kernel/power/main.c
index 540b16b68565..19122cf6d827 100644
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -14,6 +14,7 @@
#include <linux/string.h>
#include <linux/delay.h>
#include <linux/errno.h>
+#include <linux/kmod.h>
#include <linux/init.h>
#include <linux/console.h>
#include <linux/cpu.h>
@@ -237,6 +238,10 @@ static int suspend_prepare(void)
if (error)
goto Finish;
+ error = usermodehelper_disable();
+ if (error)
+ goto Finish;
+
if (suspend_freeze_processes()) {
error = -EAGAIN;
goto Thaw;
@@ -256,6 +261,7 @@ static int suspend_prepare(void)
Thaw:
suspend_thaw_processes();
+ usermodehelper_enable();
Finish:
pm_notifier_call_chain(PM_POST_SUSPEND);
pm_restore_console();
@@ -376,6 +382,7 @@ int suspend_devices_and_enter(suspend_state_t state)
static void suspend_finish(void)
{
suspend_thaw_processes();
+ usermodehelper_enable();
pm_notifier_call_chain(PM_POST_SUSPEND);
pm_restore_console();
}
diff --git a/kernel/power/user.c b/kernel/power/user.c
index a6332a313262..005b93d839ba 100644
--- a/kernel/power/user.c
+++ b/kernel/power/user.c
@@ -212,13 +212,20 @@ static long snapshot_ioctl(struct file *filp, unsigned int cmd,
case SNAPSHOT_FREEZE:
if (data->frozen)
break;
+
printk("Syncing filesystems ... ");
sys_sync();
printk("done.\n");
- error = freeze_processes();
+ error = usermodehelper_disable();
if (error)
+ break;
+
+ error = freeze_processes();
+ if (error) {
thaw_processes();
+ usermodehelper_enable();
+ }
if (!error)
data->frozen = 1;
break;
@@ -227,6 +234,7 @@ static long snapshot_ioctl(struct file *filp, unsigned int cmd,
if (!data->frozen || data->ready)
break;
thaw_processes();
+ usermodehelper_enable();
data->frozen = 0;
break;