Re: [2.6.4-rc2] bogus semicolon behind if()

From: Maciej W. Rozycki (macro_at_ds2.pg.gda.pl)
Date: 03/17/04

  • Next message: David Odin: "Patch to fix the old api for codafs" 
    Date:	Wed, 17 Mar 2004 17:51:42 +0100 (CET)
To: Thomas Schlichter <thomas.schlichter@web.de>

    On Tue, 9 Mar 2004, Thomas Schlichter wrote:

    > 2. To fix my problem, timer_ack must be set to 1 for my (integrated) APIC, and
    > as my CPU has a TSC, this cannot be correct for me:
    > - timer_ack = 1;
    > + if (nmi_watchdog == NMI_IO_APIC && !APIC_INTEGRATED(ver))
    > + timer_ack = 1;
    > + else
    > + timer_ack = !cpu_has_tsc;
    >
    > I changed that if(...) to
    > if (nmi_watchdog == NMI_IO_APIC || APIC_INTEGRATED(ver))
    > which works fine for me here, but I am not 100% sure if this is what the
    > author of the original patch ment and if it still fixes the original
    > problem...

     You need timer_ack set to one when either:

    1. you use the I/O APIC NMI watchdog and you have a discrete APIC chip
    (i.e. the 82489DX),

    or:

    2. the timer interrupt (IRQ 0) goes through one of the APICs (whatever
    way; we check three variations) and the TSC is non-functional (absent or
    disabled).

    Since you have an integrated APIC and you use the TSC, you may have
    timer_ack set to zero. That saves a few (possibly slow) I/O accesses and
    works around problems that may arise due 8259A clone (in)compatibility or
    bugs in SMM firmware.

      Maciej 

    -- 
+  Maciej W. Rozycki, Technical University of Gdansk, Poland   +
+--------------------------------------------------------------+
+        e-mail: macro@ds2.pg.gda.pl, PGP key available        +
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