Messages in this thread | | | Date | Thu, 4 Apr 2013 20:24:05 -0400 | From | Neil Horman <> | Subject | Re: [PATCH v4] irq: add quirk for broken interrupt remapping on 55XX chipsets |
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On Thu, Apr 04, 2013 at 02:11:54PM -0700, Yinghai Lu wrote: > On Thu, Apr 4, 2013 at 1:33 PM, Bjorn Helgaas <bhelgaas@google.com> wrote: > >> See my last email to Bjorn. Doing this in early-quirks in such a way that we > >> can detect an iommu that has interrupt remapping enabled (so we don't just > >> unilaterally print this quirk all the time) requires that we be able to parse > >> acpi tables very early in the boot. If you know of how to do that, I can make > >> this happen. If not, I suppose another alternative would be to have the early > >> quirk set a flag that tells us this is a bogus chip, and if we try to enable irq > >> remapping with that flag set, we should fail, and report the error at that time, > >> but I'm not sure I like that solution. > > > > I like that solution :) It seems very simple -- you don't have to > > parse any tables or anything. > > You are right, we don't need to parse any acpi tables. > > just add one quirk in early-quirk.c to set > disable_irq_remap = 1; > Well, I can't just do that. We need to issue a warning to the user as well, and to do so conditionally (we don't want to warn users who have prorperly updated BIOSes), I would need to know if irq remapping is actually on or not, which would require parsing ACPI tables
But, as noted above, I can just set a flag, and defer the printing of the warning until later in the boot process, when we know that information already. Bjorn seems on board with that idea, so I'll spin up a patch for it in the AM.
Thanks! Neil
> Thanks > > Yinghai >
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