x86: Do sanity test on pirq table before writing

If pirq_routing_table points to NULL, that means U-Boot fails to
generate the table before in create_pirq_routing_table(), so we
test it against NULL before actually writing it.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Simon Glass <sjg@chromium.org>

diff --git a/arch/x86/cpu/irq.c b/arch/x86/cpu/irq.c
index d1711af..74b89ad 100644 (file)
--- a/arch/x86/cpu/irq.c
+++ b/arch/x86/cpu/irq.c
@@ -209,5 +209,8 @@ void pirq_init(void)
 
 u32 write_pirq_routing_table(u32 addr)
 {
+       if (!pirq_routing_table)
+               return addr;
+
        return copy_pirq_routing_table(addr, pirq_routing_table);
 }