请教关于等待队列的问题

spx

在写一个AD的驱动程序。用到等待队列的地方如下所示。

结果：等待队列无法wake up。即可以打印出"will wake up"，但进程无法被wake up，即无法打印“wake up”。


static wait_queue_head_t wait;  //声明了全局静态变量


static int adcdrv_open(struct inode*inode,struct file*filp)
{
        ....
        init_waitqueue_head(&wait);
        ....
}


static ssize_t adcdrv_read(struct file* file,char* buffer,size_t count,loff_t* ppos)
{
        ....
        interruptible_sleep_on(&wait);
        printk("wake up\n");
        ....
}


static void adcdone_int_handler(int irq, void *dev_id, struct pt_regs *reg)
{
        printk("will wake up\n");
        wake_up_interruptible(&wait);
}

请各位帮忙解答，谢谢～

scutan

原帖由 spx 于 2007-8-6 16:19 发表
在写一个AD的驱动程序。用到等待队列的地方如下所示。

结果：等待队列无法wake up。即可以打印出"will wake up"，但进程无法被wake up，即无法打印“wake up”。


static wait_queue_head_t wait;  //声 ...

sleep_on()系列的函数慢慢被淘汰了. 现在一般都用wait_event()系列的.
你试试这样可以不:

1. 
   
2. int flag = 0;
   
3. static DECLARE_WAIT_QUEUE_HEAD(wq);
   
4. static ssize_t adcdrv_read(struct file* file,char* buffer,size_t count,loff_t* ppos)
   
5. {
   
6.         ....
   
7.         wait_event_interruptible(wq, flag != 0);
   
8.         printk("wake up\n");
   
9.         ....
   
10. }
    
11. 
    
12. static void adcdone_int_handler(int irq, void *dev_id, struct pt_regs *reg)
    
13. {
    
14.         printk("will wake up\n");
    
15.         flag = 1;
    
16.         wake_up_interruptible(&wq);
    
17. }
    
18. 
    
19. 
    

复制代码

spx

多谢2楼指点。但是我运行后出现如下错误：
是不是在声明和初始化的时候不对亚？

Unable to handle kernel NULL pointer dereferen                                            
Memory: 64MB =
sp : c01a1f1c  ip : 00000000  fp : c01a1f40 62540KB available (1528K code, 328K data,
r10: 00000001  r9 : c01a1f70  r8 : a0000093                        
r3 : 00000000  r2 : 00000001  r1 : c01a0000  r0 : ffffff9d
Flags: Nzcv  IRQs off  FIQs on  Mode SVC_32  Segment kernel
Control: C000317F  Table: 32B58000  DAC: 0000001D
Process swapper (pid: 0, stackpage=c01a1000)
Stack: (0xc01a1f0c to 0xc01a2000)
1f00:                            c032b3a0 c0025d7c 80000093 ffffffff c2cd25a0
1f20: 0000003e 20000000 c01b323c c01b2a7c c01bad80 c01a1f6c c01a1f44 c001a0cc
1f40: c0025d50 ea000000 c01a1fb8 00000001 c00228a8 60000013 ffffffff 30014c58
1f60: c01a1fd0 c01a1f70 c00194c0 c001a01c 00000000 00000032 0000001d c001acb0
1f80: c01a0000 c001acb0 c01a2e70 c01b32a4 c01a2c48 41129200 30014c58 c01a1fd0
1fa0: c01a1fb8 c01a1fb8 c001a5c4 c00228a8 60000013 ffffffff 00004000 c01df680
1fc0: c01b32bc c01a1fe0 c01a1fd4 c0019030 c001a588 c01a1ffc c01a1fe4 c00088bc
1fe0: c0019010 c01b36d0 c01e91f4 c01e91f4 00000000 c01a2000 c0008080 c000878c
Backtrace:
Function entered at [<c0025d40>] from [<c001a0cc>]
Function entered at [<c001a00c>] from [<c00194c0>]
Function entered at [<c001a578>] from [<c0019030>]
r6 = C01B32BC  r5 = C01DF680  r4 = 00004000
Function entered at [<c0019000>] from [<c00088bc>]
Function entered at [<c000877c>] from [<c0008080>]
Code: e1a07000 e1540007 0a000024 e514c004 (e59c3000)
Kernel panic: Aiee, killing interrupt handler!
In interrupt handler - not syncing

spx

我把初始化改回原来的
static wait_queue_head_t wait;
init_waitqueue_head(&wait);
就不会出现上面那样的错误，但是还是无法wake up进程。

scutan

那你检查一下看是不是其它地方写错了吧, wait_event()的函数的确是这样用的.

spx

那可以能是那些地方的问题亚？
求教~~

scutan

原帖由 spx 于 2007-8-6 18:24 发表
那可以能是那些地方的问题亚？
求教~~

以前使用wait_event()函数写的一个定时器, 你看看吧, 就是使用wait_event_interruptible()这个函数.
希望对你有用.

1. 
   
2. #include<linux/init.h>
   
3. #include<linux/sched.h>
   
4. #include<linux/module.h>
   
5. #include<linux/jiffies.h>
   
6. #include<asm/io.h>
   
7. #include<linux/timer.h>
   
8. #include<linux/wait.h>
   
9. 
   
10. MODULE_LICENSE("GPL");
    
11. 
    
12. static DECLARE_WAIT_QUEUE_HEAD(wq);
    
13. static int flag = 0;
    
14. struct timer_list my_timer;
    
15. 
    
16. void timer_test(unsigned long data)
    
17. {
    
18.         printk("this is a test\n");
    
19.         flag = 1;
    
20.         wake_up_interruptible(&wq);
    
21.         printk("wake it up\n");
    
22. }
    
23. 
    
24. static int __init hello_init(void)
    
25. {
    
26.         init_timer(&my_timer);
    
27.         my_timer.expires = jiffies + 5000;
    
28.         my_timer.data = 0;
    
29.         my_timer.function = timer_test;
    
30.         add_timer(&my_timer);
    
31.         wait_event_interruptible(wq, flag != 0);
    
32.         printk("I am waked\n");
    
33.         flag = 0;
    
34.         return 0;
    
35. }
    
36. 
    
37. static void __exit hello_exit(void)
    
38. {
    
39.         del_timer(&my_timer);
    
40.         printk(KERN_ALERT "Goodbye\n");
    
41. }
    
42. 
    
43. module_init(hello_init);
    
44. module_exit(hello_exit);
    
45. 
    
46. 
    

复制代码

spx

还是没有办法wake up进程。下面是我的程序代码，请帮忙解决～～

#include <linux/config.h> #include <linux/module.h> #include <linux/kernel.h> #include <linux/init.h> #include <linux/sched.h> #include <linux/irq.h> #include <linux/delay.h> #include <asm/hardware.h> #include <asm/semaphore.h> #include <asm/uaccess.h> MODULE_LICENSE("GPL"); #define IOPORT_MAJOR 220 #define START_ADC_AIN(x) \ &nbsp;&nbsp;&nbsp;&nbsp;{ \ &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;ADCCON = PRESCALE_EN | PRSCVL(255) | ADC_INPUT((x)) ; \ &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;ADCCON |= ADC_START; \ &nbsp;&nbsp;&nbsp;&nbsp;} static struct semaphore adc_lock; static  wait_queue_head_t adc_wait; static int flag=0; static ssize_t adcdrv_read(struct file*,char*,size_t,loff_t*); static int adcdrv_open(struct inode*,struct file*); struct file_operations adcdrv_fops= { &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;open:adcdrv_open, &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;read:adcdrv_read, }; //adcdone中断处理函数 static void adcdone_int_handler(int irq, void *dev_id, struct pt_regs *reg) { &nbsp;&nbsp;&nbsp;&nbsp;printk("will wake up\n"); &nbsp;&nbsp;&nbsp;&nbsp;flag=1; &nbsp;&nbsp;&nbsp;&nbsp;wake_up_interruptible(&adc_wait); } int s3c2410_adc_read(int ain) { &nbsp;&nbsp;&nbsp;&nbsp;int ret = 0; &nbsp;&nbsp;&nbsp;&nbsp;if (down_interruptible(&adc_lock)) &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;return -ERESTARTSYS; &nbsp; &nbsp;&nbsp;&nbsp;&nbsp;START_ADC_AIN(ain);  //设置ADC的参数 &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;//当AD转换结束后会触发adcdone中断，在中断中唤醒adc_wait &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;wait_event_interruptible(adc_wait,(flag!=0)); &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;printk("wake up\n"); &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;flag=0; &nbsp;&nbsp;&nbsp;&nbsp;ret = ADCDAT0 ; &nbsp;&nbsp;&nbsp;&nbsp;up(&adc_lock); &nbsp;&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp;&nbsp;printk("AIN[%d] = 0x%04x, %d\n", ain, ret, ADCCON & 0x80 ? 1:0); &nbsp;&nbsp;&nbsp;&nbsp;return (ret & 0x3ff); } static int adcdrv_open(struct inode*inode,struct file*filp) { &nbsp;&nbsp;&nbsp;&nbsp;printk("open the adc device\n"); &nbsp;&nbsp;&nbsp;&nbsp;return 0;&nbsp;&nbsp;&nbsp;&nbsp; } static ssize_t adcdrv_read(struct file* file,char* buffer,size_t count,loff_t* ppos) { &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;int ret=0; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;printk("in adcdrv_read function\n"); &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;ret=s3c2410_adc_read(6); &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;printk("the data is %d\n",ret); &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;copy_to_user(buffer,(char*)&ret,sizeof(int)); &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;return (sizeof(int)); } static int __init adcdrv_init(void) { &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;if(register_chrdev(IOPORT_MAJOR,"adc",&adcdrv_fops)) &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;{ &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;printk("adc driver register failure\n"); &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;return -1; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;} &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;else &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;{ &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;printk("adc driver register success\n"); &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;if(request_irq(IRQ_ADC_DONE, adcdone_int_handler, SA_INTERRUPT, &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;"ADC", NULL) < 0) &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;{ &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;printk("request irq failure\n"); &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;return 1; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;} &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;else &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;{ &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;printk("request irq success\n"); &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;init_MUTEX(&adc_lock); &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;init_waitqueue_head(&adc_wait); &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;ADCTSC = 0; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;return 0; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;} &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;return 0; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;} } static void __exit adcdrv_exit(void) { &nbsp;&nbsp;&nbsp;&nbsp;free_irq(IRQ_ADC_DONE, NULL); &nbsp;&nbsp;&nbsp;&nbsp;ret=unregister_chrdev(IOPORT_MAJOR,"adc"); &nbsp;&nbsp;&nbsp;&nbsp;if(ret) &nbsp;&nbsp;&nbsp;&nbsp;{ &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;printk("adc unregister failure\n"); &nbsp;&nbsp;&nbsp;&nbsp;} &nbsp;&nbsp;&nbsp;&nbsp;else &nbsp;&nbsp;&nbsp;&nbsp;{ &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;printk("adc unregister success\n"); &nbsp;&nbsp;&nbsp;&nbsp;} } module_init(adcdrv_init); module_exit(adcdrv_exit);

scutan

我没有中断处理器,还是使用我我那个定时器的小程序来模拟你的中断.试了一下你的程序,没有发现什么问题.

1. 
   
2. #include <linux/module.h>
   
3. #include <linux/kernel.h>
   
4. #include <linux/init.h>
   
5. #include <linux/fs.h>
   
6. #include <linux/sched.h>
   
7. #include <linux/irq.h>
   
8. #include <linux/delay.h>
   
9. 
   
10. #include <asm/semaphore.h>
    
11. #include <asm/uaccess.h>
    
12. 
    
13. MODULE_LICENSE("GPL");
    
14. 
    
15. static struct semaphore adc_lock;
    
16. static  wait_queue_head_t adc_wait;
    
17. static int flag=0;
    
18. 
    
19. static int Major;
    
20. struct timer_list my_timer;
    
21. 
    
22. void adcdone_int_handler(unsigned long data)
    
23. {
    
24.     printk("will wake up\n");
    
25.     flag=1;
    
26.     wake_up_interruptible(&adc_wait);
    
27.     printk("wait it up\n");
    
28. }
    
29. 
    
30. int s3c2410_adc_read(int ain)
    
31. {
    
32.     int ret = 0;
    
33. 
    
34.     if (down_interruptible(&adc_lock))
    
35.         return -ERESTARTSYS;
    
36.     printk("waiting...\n");
    
37.     wait_event_interruptible(adc_wait,(flag!=0));
    
38. 
    
39.     printk("i am waked up\n");
    
40.     flag=0;
    
41. 
    
42.     up(&adc_lock);
    
43. 
    
44.     return (10);
    
45. }
    
46. 
    
47. static int adcdrv_open(struct inode* inode,struct file* filp)
    
48. {
    
49.     printk("open the adc device\n");
    
50.     return 0;
    
51. }
    
52. 
    
53. static ssize_t adcdrv_read(struct file* file,char* buffer,size_t count,loff_t* ppos)
    
54. {
    
55.      int ret=0;
    
56.      printk("in adcdrv_read function\n");
    
57.      init_timer(&my_timer);
    
58.      my_timer.expires = jiffies + 5000;
    
59.      my_timer.data = 0;
    
60.      my_timer.function = adcdone_int_handler;
    
61.      add_timer(&my_timer);
    
62. 
    
63.      ret=s3c2410_adc_read(6);
    
64.      printk("the data is %d\n",ret);
    
65.      del_timer(&my_timer);
    
66.      copy_to_user(buffer,(char*)&ret,sizeof(int));
    
67.      return (sizeof(int));
    
68. }
    
69. 
    
70. 
    
71. static struct file_operations adcdrv_fops=
    
72. {
    
73.      .open=adcdrv_open,
    
74.      .read=adcdrv_read
    
75. };
    
76. 
    
77. static int __init adcdrv_init(void)
    
78. {
    
79.        if((Major = register_chrdev(0,"adc",&adcdrv_fops)) < 0)
    
80.        {
    
81.           printk("adc driver register failure\n");
    
82.           return -1;
    
83.         }
    
84.        else
    
85.        {
    
86.           printk("adc driver register success\n");
    
87.                   printk("Major is %d\n", Major);
    
88.           init_MUTEX(&adc_lock);
    
89.           init_waitqueue_head(&adc_wait);
    
90. 
    
91. 
    
92. 
    
93.                   return 0;
    
94.       }
    
95. }
    
96. 
    
97. static void __exit adcdrv_exit(void)
    
98. {
    
99.     int ret;
    
100.     ret=unregister_chrdev(Major,"adc");
     
101.     if(ret)
     
102.     {
     
103.         printk("adc unregister failure\n");
     
104.     }
     
105.     else
     
106.     {
     
107.         printk("adc unregister success\n");
     
108.     }
     
109. }
     
110. 
     
111. module_init(adcdrv_init);
     
112. module_exit(adcdrv_exit);
     
113. 
     
114. 
     

复制代码

这个代码是去打开这个程序的代码.
test.c

1. 
   
2. #include<stdio.h>
   
3. #include<stdlib.h>
   
4. #include<unistd.h>
   
5. #include<fcntl.h>
   
6. #include<sys/types.h>
   
7. 
   
8. int main()
   
9. {
   
10.         int fd;
    
11.         int i;
    
12.         fd = open("abc", O_RDONLY);
    
13.         if (fd < 0)
    
14.         {
    
15.                 printf("error\n");
    
16.                 return -1;
    
17.         }
    
18. 
    
19.         if (read(fd, &i, sizeof(int)) < 0)
    
20.         {
    
21.                 printf("read error\n");
    
22.                 return -1;
    
23.         }
    
24.         printf("i = %d\n", i);
    
25.         return 0;
    
26. }
    
27. 
    

复制代码

运行之后dmesg可以查看到如下结果.

adc driver register success
Major is 253
open the adc device
in adcdrv_read function
waiting...
will wake up
wait it up
i am waked up
the data is 10

这个模拟程序与你那个应该是差不多的. 我这儿运行是没有问题的.

[ 本帖最后由 scutan 于 2007-8-7 11:54 编辑 ]

spx

我把你的程序拿去运行，结果还是不行，只运行到“will wake up”就停住了。
我是在嵌入式linux下运行，内核版本是2.4.18

open the adc device
in adcdrv_read function
waiting...
will wake up