[FIX] deadlock, when calling wake_up_interruptible()

use work queue, for when calling wake_up_interruptible()

Change-Id: I247a4e85aacac7cad2729ffbe40276210183ff3c
Signed-off-by: Vyacheslav Cherkashin <v.cherkashin@samsung.com>

diff --git a/driver/device_driver.c b/driver/device_driver.c
index 07913d3..af7f9e5 100644 (file)
--- a/driver/device_driver.c
+++ b/driver/device_driver.c
@@ -34,6 +34,7 @@
 #include <linux/sched.h>
 #include <linux/module.h>
 #include <linux/wait.h>
+#include <linux/workqueue.h>
 #include <asm/uaccess.h>
 
 #include <ksyms/ksyms.h>
@@ -96,6 +97,32 @@ static struct device *swap_device_device = NULL;
 /* Reading tasks queue */
 static DECLARE_WAIT_QUEUE_HEAD(swap_device_wait);
 
+
+static atomic_t flag_wake_up = ATOMIC_INIT(0);
+
+static void __bottom_wake_up(void)
+{
+       if (waitqueue_active(&swap_device_wait))
+               wake_up_interruptible(&swap_device_wait);
+}
+
+static void bottom_wake_up(struct work_struct *work)
+{
+       if (atomic_read(&flag_wake_up)) {
+               atomic_set(&flag_wake_up, 0);
+               __bottom_wake_up();
+       }
+}
+
+static DECLARE_WORK(w_wake_up, bottom_wake_up);
+
+static void exit_w_wake_up(void)
+{
+       flush_scheduled_work();
+       __bottom_wake_up();
+}
+
+
 /* We need this realization of splice_shrink_spd() because of the its desing
  * frequent changes that I have encountered in custom kernels */
 void swap_device_splice_shrink_spd(struct pipe_inode_info *pipe,
@@ -192,6 +219,8 @@ init_fail:
 /* Unregister device TODO Check wether driver is registered */
 void swap_device_exit(void)
 {
+       exit_w_wake_up();
+
        splice_to_pipe_p = NULL;
        splice_grow_spd_p = NULL;
 
@@ -436,7 +465,10 @@ swap_device_splice_read_error:
 
 void swap_device_wake_up_process(void)
 {
-       wake_up_interruptible(&swap_device_wait);
+       if (atomic_read(&flag_wake_up) == 0) {
+               atomic_set(&flag_wake_up, 1);
+               schedule_work(&w_wake_up);
+       }
 }
 
 void set_msg_handler(msg_handler_t mh)