Bug 9153

Summary:	PnPACPI ignores IOAPIC Interrupt Source Overrides
Product:	ACPI	Reporter:	Len Brown (lenb)
Component:	Config-Interrupts	Assignee:	Shaohua (shaohua.li)
Status:	CLOSED CODE_FIX
Severity:	normal	CC:	acpi-bugzilla, amax, lcm, lpechacek, ole
Priority:	P1
Hardware:	All
OS:	Linux
Kernel Version:	up through 2.6.23	Subsystem:
Regression:	---	Bisected commit-id:
Attachments:	patch MADT DSDT patch updated patch

Description Len Brown 2007-10-12 13:38:59 UTC

This problem has always been present in the PNPACPI code.
It has shown up on i386, since PNPACPI was deployed there first.
But now that PNPACPI is included in x86_64 by default also,
and so the issue will spread there too.

The workaround is to boot with "pnpacpi=off"

This issue was diagnosed by IBM here:
https://bugzilla.novell.com/show_bug.cgi?id=214809

The RTC fails in IOAPIC mode due to mis-programmed IRQ8 polarity.
There is an Interrupt Source Override for IRQ8 -- Edge LOW.
The legacy mapping implicitly asks for,
and the DSDT explicitly asks for, Edge HIGH.

Linux first programs IRQ8 according to the Interrupt Source
Override -- but PNPACPI later runs and re-programs it
according to the DSDT.

So, PNPACPI needs to learn about Interupt Source Overrides
in IOAPIC mode, and must honor them.

Comment 1 Shaohua 2007-10-14 17:50:39 UTC

please check if the workaroud in 'http://bugzilla.kernel.org/show_bug.cgi?id=5243' works for you? AKPM already includes the workaround in -mm.

Comment 2 Shaohua 2007-10-14 18:02:16 UTC

Oh, sounds no, so the IRQ should be edge low instead of edge high? can you please attach the acpidump, I can't access the novell bugzilla.

Comment 3 Shaohua 2007-10-14 23:18:07 UTC

Created attachment 13159 [details]
patch

Could you please try attached patch? With it, interrupt override is considered.

Comment 4 Max Asbock 2007-10-15 15:25:44 UTC

I tried the patch from comment #3. 
The 2.6.23-mm1 kernel without the patch re-programs the RTC interrupt with the wrong polarity.
With the patch applied the RTC interrupt works as expected, i.e the override in the MADT is being respected.
There is one problem with the patch: it causes the following warning:
WARNING: vmlinux.o(.text+0x166c5): Section mismatch: reference to .init.text:MPBIOS_polarity (between 'acpi_get_override_irq' and 'IO_APIC_get_PCI_irq_vector')
The acpi_get_override_irq function uses MPBIOS_polarity which is declared as __init.

Comment 5 Max Asbock 2007-10-15 15:27:50 UTC

Created attachment 13173 [details]
MADT 

Here is the MADT of the affected system, showing the IRQ override for IRQ 8

Comment 6 Max Asbock 2007-10-15 15:29:18 UTC

Created attachment 13174 [details]
DSDT

Here is the DSDT (disassembled) of the affected system showing the PNP entry for IRQ8

Comment 7 Shaohua 2007-10-15 18:05:54 UTC

Created attachment 13175 [details]
patch

Ok, fixed the warning. Let's wait if it fix the bug 5243.

Comment 8 Shaohua 2007-10-25 17:42:17 UTC

*** Bug 5243 has been marked as a duplicate of this bug. ***

Comment 9 Shaohua 2007-10-25 18:15:33 UTC

Created attachment 13282 [details]
updated patch

This is the updated patch. Just move one '\n' and refreshed it against latest git tree, no functional change

Comment 10 Fu Michael 2007-11-12 17:41:12 UTC

*** Bug 7679 has been marked as a duplicate of this bug. ***

Comment 11 Len Brown 2007-11-16 22:15:47 UTC

The patch in comment #9
1. fixes the screaming IRQ8 on the STL2 in bug 5243.
2. is applied to acpi test branch

Comment 12 Len Brown 2007-12-03 22:38:06 UTC

shipped in linux-2.6.24-rc4
closed