Messages in this thread | | | Date | Tue, 22 Jul 2008 15:56:29 +0200 | From | Michal Schmidt <> | Subject | Re: PCI: MSI interrupts masked using prohibited method |
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On Fri, 18 Jul 2008 11:33:10 +0100 David Vrabel <david.vrabel@csr.com> wrote:
> Matthew Wilcox wrote: > > > > I think David's original patch (just declining to mask the > > interrupt) is the best approach to take. Perhaps architectures > > with saner interrupt hardware would like to try the approach I've > > mentioned here. > > > > I don't like the comment in http://lkml.org/lkml/2008/6/27/199 as > > it's not prohibited ... just a bad idea. How about this patch? > > The PCI specification is quite clear that it's prohibited. The > problem also is more severe than simply having spurious interrupts -- > with some devices if a line interrupt is generated (regardless of > whether it ends up on the bus) then no more interrupts are generated. > > I also think that the change requires a comment in the code. It odd > to have a mask function that doesn't really mask so a comment is > necessary to explain why this is. > > Please apply this instead. > > David
This breaks the setting of SMP affinity for MSI interrupts :-( With the patch, writes to /proc/irq/<n>/smp_affinity are ignored for an MSI interrupt.
Michal
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