On Mon, 18 Dec 2000, Petr Vandrovec wrote:
> It is possible. But it is hard to track, as it works with serial console,
> and it is not possible to paint characters to VGA screen, as vgacon uses
> hardware panning instead of scrolling :-( And if it dies, shift-pageup
> apparently does not work... And filling whole 32KB with some char
> does not work, as it changes timing too much...
Just disable the problematic printk()s for making tests (you may just
undefine APIC_DEBUG in include/asm-i386/apic.h) -- we already know what is
going to be printed here. ;-)
> No, I'll try. It occured with either AGP (Matrox G200/G400/G450) or
> PCI (S3, CL5434) VGA adapter. I did not tried real ISA VGA...
Oops, I've forgotten there exist non-ISA display adapters. ;-) Just try
if accessing one bus or another changes the behaviour.
> Yes. I could understand if I had to place bigger udelay() after INIT IPI,
> as this can cause some specific PIII initialization and Intel says that
> there should not be any MESI traffic during this init (at least I understand
Hmm, weird -- for integrated APICs an INIT IPI is about the same as
shutdown apart from the fact an NMI won't wake up a CPU (that might
actually be the local APIC not passing NMIs to the CPU in this case,
though).
> it that way). But after startup IPI it should just start executing code...
> I tried to put 'wbinvd' here and there, but it did not make any change,
> only udelay() between startup IPI cmd and first printk() did.
Hmm, a startup IPI is rather fast so the code just after issuing it may
somehow interact with the application's CPU trampoline. But try to
disable CONFIG_X86_GOOD_APIC, yet (you may configure for classic Pentium,
for example), and see if that changes anything (it shouldn't, but who
knows...).
> I have no idea. I know that board has VT82C694X (rev c4) host and PCI bridge,
Just look at the board and search for an I/O APIC chip. ;-)
> and VT82C686 (rev 22) ISA bridge. I tried to request documentation
> of 694X from VIA, but I did not heard from them. They have probably
> some secrets hidden in their hardware...
They wan't to keep the competition from being bug-compatible, it would
seem...
Maciej
-- + Maciej W. Rozycki, Technical University of Gdansk, Poland + +--------------------------------------------------------------+ + e-mail: macro@ds2.pg.gda.pl, PGP key available +- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/
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