lkml.org 
[lkml]   [2008]   [Jun]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: linux-next: Tree for June 13: IO APIC breakage on HP nx6325
    [Maciej W. Rozycki - Wed, Jun 18, 2008 at 11:36:16PM +0100]
    | On Wed, 18 Jun 2008, Cyrill Gorcunov wrote:
    |
    | > | 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)
    |
    | No, but that's an interesting observation, thank you -- well spotted!
    |
    | ExtINTA stands for an "External INTA cycle" which is passed through from
    | the CPU down to the system bus instead of being intercepted by the local
    | APIC unit as usually. In response to the INTA cycle one of the 8259A
    | chips (either the master or the slave, depending on the source of the
    | interrupt selected for handling) supplies the vector directly to the CPU
    | through PCI (or whatever kind of bus links the legacy bridge with the host
    | bridge) and then the FSB. Therefore the vector bypasses all the APIC
    | circuitry and cannot result in an APIC error interrupt.
    |
    | Instead the message quoted means an APIC input is misprogrammed
    | somewhere. This error happens if an interrupt is signalled to an unmasked
    | APIC input which uses the Fixed or Lowest-Priority delivery mode and its
    | vector implies priority below the minimum permitted, that is in the range
    | from 0 to 15.
    |
    | We have code already in place in io_apic_{32,64}.c that can be used to
    | find out the offender with a piece of code like this (#if 0 has to be
    | deactivated for this to work and they may be bit rot bugs to be fixed):
    |
    | int __init all_pic_dump(void)
    | {
    | int v = apic_verbosity;
    |
    | apic_verbosity = APIC_DEBUG;
    | print_IO_APIC();
    | print_all_local_APICs();
    | print_PIC();
    | apic_verbosity = v;
    |
    | return 0;
    | }
    |
    | late_initcall(all_pic_dump);
    |
    | if somebody is willing to aid with debugging this problem.
    |
    | Maciej
    |

    Thanks, Maciej,

    i would really like to help... but I can't even hit this
    bug on my laptop :(

    - Cyrill -


    \
     
     \ /
      Last update: 2008-06-20 21:03    [W:0.023 / U:0.024 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site