freezer: introduce freezer-friendly waiting macros

Introduce freezer-friendly wrappers around wait_event_interruptible() and
wait_event_interruptible_timeout(), originally defined in <linux/wait.h>, to
be used in freezable kernel threads.  Make some of the freezable kernel
threads use them.

This is necessary for the freezer to stop sending signals to kernel threads,
which is implemented in the next patch.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Cc: Nigel Cunningham <nigel@nigel.suspend2.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

6 files changed, 7 insertions, 13 deletions

diff --git a/drivers/input/gameport/gameport.c b/drivers/input/gameport/gameport.c
index 20896d5e5f..ec1b6cfefc 100644
--- a/drivers/input/gameport/gameport.c
+++ b/drivers/input/gameport/gameport.c
@@ -448,9 +448,8 @@ static int gameport_thread(void *nothing)
         set_freezable();
         do {
                 gameport_handle_event();
-                wait_event_interruptible(gameport_wait,
+                wait_event_freezable(gameport_wait,
                         kthread_should_stop() || !list_empty(&gameport_event_list));
-                try_to_freeze();
         } while (!kthread_should_stop());
 
         printk(KERN_DEBUG "gameport: kgameportd exiting\n");
diff --git a/drivers/input/serio/serio.c b/drivers/input/serio/serio.c
index b3bc15acd3..7f5293828f 100644
--- a/drivers/input/serio/serio.c
+++ b/drivers/input/serio/serio.c
@@ -387,9 +387,8 @@ static int serio_thread(void *nothing)
         set_freezable();
         do {
                 serio_handle_event();
-                wait_event_interruptible(serio_wait,
+                wait_event_freezable(serio_wait,
                         kthread_should_stop() || !list_empty(&serio_event_list));
-                try_to_freeze();
         } while (!kthread_should_stop());
 
         printk(KERN_DEBUG "serio: kseriod exiting\n");
diff --git a/drivers/input/touchscreen/ucb1400_ts.c b/drivers/input/touchscreen/ucb1400_ts.c
index 86aed64ec0..89373b01d8 100644
--- a/drivers/input/touchscreen/ucb1400_ts.c
+++ b/drivers/input/touchscreen/ucb1400_ts.c
@@ -333,10 +333,9 @@ static int ucb1400_ts_thread(void *_ucb)
                         timeout = msecs_to_jiffies(10);
                 }
 
-                wait_event_interruptible_timeout(ucb->ts_wait,
+                wait_event_freezable_timeout(ucb->ts_wait,
                         ucb->irq_pending || ucb->ts_restart || kthread_should_stop(),
                         timeout);
-                try_to_freeze();
         }
 
         /* Send the "pen off" if we are stopping with the pen still active */
diff --git a/drivers/media/dvb/dvb-core/dvb_frontend.c b/drivers/media/dvb/dvb-core/dvb_frontend.c
index b203640ef1..445f026655 100644
--- a/drivers/media/dvb/dvb-core/dvb_frontend.c
+++ b/drivers/media/dvb/dvb-core/dvb_frontend.c
@@ -527,7 +527,8 @@ static int dvb_frontend_thread(void *data)
                 up(&fepriv->sem);           /* is locked when we enter the thread... */
 restart:
                 timeout = wait_event_interruptible_timeout(fepriv->wait_queue,
-                        dvb_frontend_should_wakeup(fe) || kthread_should_stop(),
+                        dvb_frontend_should_wakeup(fe) || kthread_should_stop()
+                                || freezing(current),
                         fepriv->delay);
 
                 if (kthread_should_stop() || dvb_frontend_is_exiting(fe)) {
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 60a8f55a0c..036c3dea85 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -2870,10 +2870,9 @@ static int hub_thread(void *__unused)
         set_freezable();
         do {
                 hub_events();
-                wait_event_interruptible(khubd_wait,
+                wait_event_freezable(khubd_wait,
                                 !list_empty(&hub_event_list) ||
                                 kthread_should_stop());
-                try_to_freeze();
         } while (!kthread_should_stop() || !list_empty(&hub_event_list));
 
         pr_debug("%s: khubd exiting\n", usbcore_name);
diff --git a/drivers/usb/storage/usb.c b/drivers/usb/storage/usb.c
index 3451e8d03a..ac6114eea0 100644
--- a/drivers/usb/storage/usb.c
+++ b/drivers/usb/storage/usb.c
@@ -907,12 +907,9 @@ static int usb_stor_scan_thread(void * __us)
         if (delay_use > 0) {
                 printk(KERN_DEBUG "usb-storage: waiting for device "
                                 "to settle before scanning\n");
-retry:
-                wait_event_interruptible_timeout(us->delay_wait,
+                wait_event_freezable_timeout(us->delay_wait,
                                 test_bit(US_FLIDX_DISCONNECTING, &us->flags),
                                 delay_use * HZ);
-                if (try_to_freeze())
-                        goto retry;
         }
 
         /* If the device is still connected, perform the scanning */