diff --git a/Chapter8_SOC_与_Linux/8.7_设备驱动中的并发控制.md b/Chapter8_SOC_与_Linux/8.7_设备驱动中的并发控制.md
index 6500e97..f79f997 100644
--- a/Chapter8_SOC_与_Linux/8.7_设备驱动中的并发控制.md
+++ b/Chapter8_SOC_与_Linux/8.7_设备驱动中的并发控制.md
@@ -340,7 +340,7 @@ struct demo_dev
 {
     struct cdev cdev;
     struct device *dev;
-    rwlock_t demo_rwlock;
+    struct rw_semaphore demo_rwsemp;
     // This is a test.
     char demo_text[DEMO_DATA_SIZE];
 };
@@ -351,7 +351,7 @@ static ssize_t demo_read(struct file *filp, char __user *buffer, size_t count, l
     loff_t p;
     ssize_t ret = 0;
 
-    read_lock(&devp->demo_rwlock);
+    down_read(&devp->demo_rwsemp);
     p = *position;
 
     // This is a test.
@@ -362,13 +362,13 @@ static ssize_t demo_read(struct file *filp, char __user *buffer, size_t count, l
         count = DEMO_DATA_SIZE-p;
 
     if(copy_to_user((void*)buffer, &devp->demo_text[p], count)) {
-        read_unlock(&devp->demo_rwlock);
+        up_read(&devp->demo_rwsemp);
         ret = -EFAULT;
     }
     else
     {
         *position += count;
-        read_unlock(&devp->demo_rwlock);
+        up_read(&devp->demo_rwsemp);
         ret = count;
     }
     return ret;
@@ -380,7 +380,7 @@ static ssize_t demo_write(struct file *filp, const char __user *buffer, size_t c
     loff_t p;
     ssize_t ret = 0;
 
-    write_lock(&devp->demo_rwlock);
+    down_write(&devp->demo_rwsemp);
     p = *position;
     // This is a test.
     // 分析和获取有效的写长度
@@ -390,12 +390,12 @@ static ssize_t demo_write(struct file *filp, const char __user *buffer, size_t c
         count = DEMO_DATA_SIZE-p;
 
     if(copy_from_user(&devp->demo_text[p], (void*)buffer, count)) {
-        write_unlock(&devp->demo_rwlock);
+        up_write(&devp->demo_rwsemp);
         ret = -EFAULT;
     }
     else {
         *position += count;
-        write_unlock(&devp->demo_rwlock);
+        up_write(&devp->demo_rwsemp);
         ret = count;
     }
 
@@ -426,7 +426,7 @@ static int demo_setup_cdev(struct demo_dev *devp, int index)
     devp->demo_text[DEMO_DATA_SIZE-1] = 0;
     sprintf(devp->demo_text, "%d", index);
 
-    rwlock_init(&devp->demo_rwlock);
+    init_rwsem(&devp->demo_rwsemp);
     return 0;
 out_cdev:
     cdev_del(&devp->cdev);