binder: use freezable blocking calls

Avoid waking up every thread sleeping in a binder call during
suspend and resume by calling a freezable blocking call.  Previous
patches modified the freezer to avoid sending wakeups to threads
that are blocked in freezable blocking calls.

This call was selected to be converted to a freezable call because
it doesn't hold any locks or release any resources when interrupted
that might be needed by another freezing task or a kernel driver
during suspend, and is a common site where idle userspace tasks are
blocked.

Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/staging/android/binder.c

@@ -20,6 +20,7 @@
 #include <asm/cacheflush.h>
 #include <linux/fdtable.h>
 #include <linux/file.h>
+#include <linux/freezer.h>
 #include <linux/fs.h>
 #include <linux/list.h>
 #include <linux/miscdevice.h>
@@ -2140,13 +2141,13 @@ static int binder_thread_read(struct binder_proc *proc,
 			if (!binder_has_proc_work(proc, thread))
 				ret = -EAGAIN;
 		} else
-			ret = wait_event_interruptible_exclusive(proc->wait, binder_has_proc_work(proc, thread));
+			ret = wait_event_freezable_exclusive(proc->wait, binder_has_proc_work(proc, thread));
 	} else {
 		if (non_block) {
 			if (!binder_has_thread_work(thread))
 				ret = -EAGAIN;
 		} else
-			ret = wait_event_interruptible(thread->wait, binder_has_thread_work(thread));
+			ret = wait_event_freezable(thread->wait, binder_has_thread_work(thread));
 	}
 
 	binder_lock(__func__);