I have kernel timer which check for flag. if(flag ) { igb_down(adapter); } else { igb_up(adapter); } I could see a kernel crash; because there are a lot of msleep() in igb_down function. #define msleep(x) do { set_current_state(TASK_UNINTERRUPTIBLE); \ schedule_timeout((x * HZ)/1000 + 2); \ } while (0) sleep() is called from bottom half context; this is the cause of kernel crash. 1) Since timer call back dont have process context associated with it; i think , "current" points to the last preempted task ? 2) How can i introduce delays in interrupt context to avoid the kernel crash. mdelay() will work ? 3) is there any better mechanism to do this job ? Thanks, Ratheesh -- To unsubscribe from this list: send the line "unsubscribe linux-newbie" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.linux-learn.org/faqs