[Maciej W. Rozycki - Wed, Jun 18, 2008 at 05:02:48AM +0100]
| On Wed, 18 Jun 2008, Rafael J. Wysocki wrote:
|
| > Here you go. Below is the relevant snippet from the yesterday's linux-next
| > dmesg with the patches:
| > "x86: I/O APIC: timer through 8259A second-chance"
| > "x86: add C1E aware idle function"
| > reverted and the appended debug patch applied.
| >
| > [ 0.108006] TIMER: vector=0x30 apic1=0 pin1=2 apic2=-1 pin2=-1
| > [ 0.108006] ..MP-BIOS bug: 8254 timer not connected to IO-APIC
| > [ 0.108006] ...trying to set up timer (IRQ0) through the 8259A ... <2> failed
| > [ 0.108006] ...trying to set up timer as Virtual Wire IRQ...<2> works.
| >
| > The entire dmesg is at: http://www.sisk.pl/kernel/debug/20080616/dmesg-4.log
|
| Thanks -- this is very important and useful information as it shows the
| exact alternative used.
|
| With such a configuration the "x86: I/O APIC: timer through 8259A
| second-chance" patch should not matter, because the only change it
| introduces is an attempt to try the same I/O APIC pin again, but with the
| IRQ0 line of the master 8259A enabled. That's not a terribly unusual
| configuration and nothing should get confused in the system.
|
| Barring the unlikely possibility of the 8259A actually being wired to
| INTIN2 of the I/O APIC I can see two possible explanations:
|
| 1. The 8259A interrupt actually escapes to the CPU somehow and is handled
| as an ExtINTA interrupt. This would make the code in check_timer()
| decide it has found a working configuration, while actually it has been
| fooled.
Maciej, that is why we get 'received illegal vector'?
[ 129.092151] APIC error on CPU1: 00(40)
|
| 2. There is a bug in this patch or an assumption it makes which results
| in the state of some component not to be restored correctly.
| Unfortunately I have no resources to test the 64-bit variation of the
| code, so something may have escaped my attention.
|
| I'd like to find out which one is the case -- can you please reapply the
| patch and send me the corresponding section of the bootstrap log? If the
| system hangs before you can retrieve the log, please just place:
|
| while (1);
|
| or something like that after the out: label in check_timer().
|
| Thanks.
|
| Maciej
|
- Cyrill -
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