arch/x86/ioapic: Clear vector table first

Always clear vector 0 entry before optionally overwriting it
with the i8259 timer redirection.

Change-Id: Ia2e96f43e6494711f9fc4fd74229f5817b04b48d
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/55286
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Furquan Shaikh <furquan@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

1 files changed, 2 insertions, 8 deletions

diff --git a/src/arch/x86/ioapic.c b/src/arch/x86/ioapic.c
index d2f65fdaf3..a11e5dd9b3 100644
--- a/src/arch/x86/ioapic.c
+++ b/src/arch/x86/ioapic.c
@@ -138,17 +138,11 @@ void ioapic_set_boot_config(void *ioapic_base, bool irq_on_fsb)
 
 void setup_ioapic_helper(void *ioapic_base, u8 ioapic_id, bool enable_virtual_wire)
 {
-	int first = 0, last;
-
 	set_ioapic_id(ioapic_base, ioapic_id);
+	clear_ioapic(ioapic_base);
 
-	if (enable_virtual_wire) {
+	if (enable_virtual_wire)
 		route_i8259_irq0(ioapic_base);
-		first = 1;
-	}
-
-	last = ioapic_interrupt_count(ioapic_base) - 1;
-	clear_vectors(ioapic_base, first, last);
 }