Problem with schedule_timeout() and udelay() in kernel module

[Ian Yap <d2army@xxxxxxxxx>]

Hi there everyone,

I have realized that when I use schedule_timeout and
udelay one after another in a kernel module code, the
udelay doesn't seem to execute when its time parameter
is less than 1000( i.e. less than 1ms).  

It seems that schedule_timeout uses ms and if delay in
udelay(delay) is less than 1ms, it is treated as zero.
It seems whenever schedule_timeout appears, the
minimal unit is ms. 

This is the code segment

......
if(delay < 1000)
        udelay(delay);
 else
 {
       set_current_state(TASK_UNINTERRUPTIBLE);
       schedule_timeout (delay/1000);
                
       if(delay >= 1000){
       delay2=delay%1000;
       udelay(delay2);}
 }
.......

For some reason, the udelay here doesn't seem to
execute when we check using the time command
 
I was wondering if anyone has encountered issued like
this before 

Thanks in advance!

I.S.


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