Messages in this thread | | | Date | Mon, 24 Jan 2011 18:00:57 +0300 | From | Alexander Gordeev <> | Subject | Re: PPS parport boot lockup: INFO: HARDIRQ-READ-safe -> HARDIRQ-READ-unsafe lock order detected |
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В Fri, 21 Jan 2011 08:37:34 -0800 Linus Torvalds <torvalds@linux-foundation.org> пишет:
> On Fri, Jan 21, 2011 at 6:44 AM, Alexander Gordeev > <lasaine@lvk.cs.msu.su> wrote: > > > > But parport_unregister_device should probably never be called while > > parport interrupts are enabled (in hardware). So this is a false > > positive. Is this right? > > "Enabled in hardware" is immaterial - with shared interrupts, it > doesn't matter one whit whether parport interrupts are disabled on the > chip, because some other chip may be using the same interrupt line. > > So you'd need to have something that guarantees that there is no > concurrent use, like actually unregistering the irq handler itself. > Things like that can work. > > HOWEVER, even then I think you should see the lockdep message as a > problem. The automated toolchain is great because it shows problems > that it thinks might happen - not when they happen, but based on a > simpler theoretical model. Ignoring the error because there is some > rule in place that is hard to explain to the automated toolchain is > the wrong thing to do, because it makes the lockdep automation less > reliable. > > Think of it as a compiler warning - maybe the warning doesn't actually > imply an actual bug, but you should strive to write code that doesn't > warn, because otherwise the noise from the warning you ignored will > make it harder for others to see the _real_ bugs. > > Linus
Ok, thank you very much for clarification! I'll send the patch as reply to the first e-mail.
-- Alexander [unhandled content-type:application/pgp-signature] | |