Messages in this thread |  | | | From | "Manfred Spraul" <> | | Subject | Re: sleep_on, wake_up question | | Date | Thu, 30 Dec 1999 16:17:18 +0100 |
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From: "Richard B. Johnson" <root@chaos.analogic.com> > > There is more at work than your code implies. If the interrupt occurs > instantly, before your call to interruptible_sleep_on(), the call will > return immediately. It works. I have many drivers using this technique > and they have never missed a beat. > No. Do not use sleep_on() in new drivers. sleep_on() can miss interrupts unless you own the global interrupt lock(*). Your driver could fail on SMP.
Please use either wait_event() [only possible if you don't use spinlocks], or manually implement sleep_on(): [wait_event() + spin_unlock_irq() just before schedule() + spin_lock_irq() just behind schedule()].
It's implemented in <linux/sched.h> for both 2.2 and 2.3
(*) or lock_kernel(), but this is only possible from outside interrupt contexts. -- Manfred
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