On Fri, May 04, 2007 at 11:24:33AM -0700, Don Fry wrote: > All instances of obtaining the lock in pcnet32 are done as > spin_lock_irqsave except the interrupt handler itself. The interrupt mask > needs to be saved everywhere else, but the interrupt handler is known not > to need to save the flags. > > If the lock is held and the same CPU tries to get the lock again, it will > wait a very long time ;-(. I believe the locking is fine for a > non-preemptable kernel, but I have little experience with a preemptable > kernel. > > When does a preemptable kernel allow interrupts to occur?
I have no idea actually. > Is there a bug in this particular architectures locking code? On i386? I hope not. > From looking at preempt-locking.txt the driver has (1) no per-cpu data, > (2) 'CPU state protection' should be fine, > (3) the 'lock is acquired and released by the same task'. > I don't see a problem unless I am misunderstanding something. Well I don't know, but something is going wrong and causing the soft lock up. I must admit I am surprised if an interrupt can occour while handling an interrupt, but then again maybe that is supposed to be allowed. -- Len Sorensen - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
