Messages in this thread Patch in this message | | | Subject | [PATCH] linux-2.4.22_clear-smi-fix_A0 | From | john stultz <> | Date | 25 Aug 2003 18:23:42 -0700 |
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Marcelo, All,
Some of our more recent hardware requires that SMIs are routed through the IOAPIC, thus when we clear_IO_APIC() at boot time, we clear the BIOS initialized SMI pin (which is unfortunately not described in the MPS or ACPI tables). This basically clobbers the SMI, which can cause problems with console redirection as well keeping us from being able to transition into full ACPI mode.
This patch (back ported from 2.5) simply reads the apic entry in clear_IO_APIC to make sure the delivery_mode isn't dest_SMI. If it is, we leave the apic entry alone and return.
With this patch, booting with full ACPI works and SMIs function properly.
Please consider for acceptance.
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 Mon Aug 25 14:10:12 2003 +++ b/arch/i386/kernel/io_apic.c Mon Aug 25 14:10:12 2003 @@ -169,6 +169,14 @@ { struct IO_APIC_route_entry entry; unsigned long flags; + + /* Check delivery_mode to be sure we're not clearing an SMI pin */ + spin_lock_irqsave(&ioapic_lock, flags); + *(((int*)&entry) + 0) = io_apic_read(apic, 0x10 + 2 * pin); + *(((int*)&entry) + 1) = io_apic_read(apic, 0x11 + 2 * pin); + spin_unlock_irqrestore(&ioapic_lock, flags); + if (entry.delivery_mode == dest_SMI) + return; /* * Disable it in the IO-APIC irq-routing table:
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