John,
That looks reasonable to me. The one possible catch would be for systems so
old they don't do SMI -- 386s and 486s, I imagine. If this code doesn't barf
on them when CONFIG_IO_APIC is turned on, then it should be fine (minus the
printk).
(I believe there was at least one such system, the Intel Xpress box. It
contained a 486 and seperate APIC chips.)
James
On Tuesday 06 May 2003 02:58 pm, john stultz wrote:
> All,
> I've been having problems with ACPI on a box here in our lab, it ends
> up that when we clear_IO_APIC() at boot time, we clear the SMI pin that
> is setup by the BIOS. This basically clobbers the SMI and we can then
> never make the transition into ACPI mode.
>
> I'm not sure if this is the right solution, but I figured I'd post it
> and take the flamage if I'm just being dumb. Basically in
> clear_IO_APIC_pin, I read the apic entry to make sure the delivery_mode
> isn't dest_SMI. If it is, we leave the apic entry alone and return.
>
> With this patch, the box boots and SMIs appear to function properly.
>
> Let me know if you have any thoughts or suggestions.
>
> thanks
> -john
>
>
> diff -Nru a/arch/i386/kernel/io_apic.c b/arch/i386/kernel/io_apic.c
> --- a/arch/i386/kernel/io_apic.c Tue May 6 14:46:58 2003
> +++ b/arch/i386/kernel/io_apic.c Tue May 6 14:46:58 2003
> @@ -219,6 +219,14 @@
> {
> struct IO_APIC_route_entry entry;
> unsigned long flags;
> +
> + /* Check delivery_mode to be sure we're not clearing an SMI pin */
> + *(((int*)&entry) + 0) = io_apic_read(apic, 0x10 + 2 * pin);
> + *(((int*)&entry) + 1) = io_apic_read(apic, 0x11 + 2 * pin);
> + if (entry.delivery_mode == dest_SMI){
> + printk(KERN_INFO "apic %i pin %i is an SMI pin!\n", apic, pin);
> + return;
> + }
>
> /*
> * Disable it in the IO-APIC irq-routing table:
--
James Cleverdon
IBM xSeries Linux Solutions
{jamesclv(Unix, preferred), cleverdj(Notes)} at us dot ibm dot com
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