1 files changed, 7 insertions, 1 deletions

diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index c7bb6c69f21c..d6af97fd170a 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -2438,7 +2438,13 @@ unsigned int arch_dynirq_lower_bound(unsigned int from)
          * dmar_alloc_hwirq() may be called before setup_IO_APIC(), so use
          * gsi_top if ioapic_dynirq_base hasn't been initialized yet.
          */
-        return ioapic_initialized ? ioapic_dynirq_base : gsi_top;
+        if (!ioapic_initialized)
+                return gsi_top;
+        /*
+         * For DT enabled machines ioapic_dynirq_base is irrelevant and not
+         * updated. So simply return @from if ioapic_dynirq_base == 0.
+         */
+        return ioapic_dynirq_base ? : from;
 }
 
 #ifdef CONFIG_X86_32