diff --git a/target/linux/lantiq/patches-4.14/0400-Revert-MIPS-smp-mt-Use-CPU-interrupt-controller-IPI-.patch b/target/linux/lantiq/patches-4.14/0400-Revert-MIPS-smp-mt-Use-CPU-interrupt-controller-IPI-.patch
new file mode 100644
index 0000000000000000000000000000000000000000..7c2deb190e144f914f4a8717ed5fb11971de79a3
--- /dev/null
+++ b/target/linux/lantiq/patches-4.14/0400-Revert-MIPS-smp-mt-Use-CPU-interrupt-controller-IPI-.patch
@@ -0,0 +1,271 @@
+From 8fe9821b478e5c61fef4786b7ec96b6766af196d Mon Sep 17 00:00:00 2001
+From: Mathias Kresin <dev@kresin.me>
+Date: Mon, 8 Jan 2018 23:04:57 +0100
+Subject: [PATCH] Revert "MIPS: smp-mt: Use CPU interrupt controller IPI IRQ
+ domain support"
+
+The problem is that the Lantiq IRQ controller gets registered first and
+it directly handles the MIPS native SW1/2 and HW0 - HW5 IRQs. It looks
+like this controller already registers IRQ 0 - 7 and the generic driver
+only gets the following IRQs starting later.
+
+The upstream discussion can be found at https://www.linux-mips.org/archives/linux-mips/2017-05/msg00059.html
+
+This reverts kernel commit 1eed40043579 ("MIPS: smp-mt: Use CPU interrupt
+controller IPI IRQ domain support").
+
+Signed-off-by: Mathias Kresin <dev@kresin.me>
+
+---
+ arch/mips/kernel/smp-mt.c | 49 ++++++++++++++++++++++--
+ arch/mips/lantiq/irq.c | 52 ++++++++++++++++++++++++++
+ arch/mips/mti-malta/malta-int.c | 83 +++++++++++++++++++++++++++++++++++++++--
+ 3 files changed, 176 insertions(+), 8 deletions(-)
+
+--- a/arch/mips/kernel/smp-mt.c
++++ b/arch/mips/kernel/smp-mt.c
+@@ -83,8 +83,6 @@ static unsigned int __init smvp_vpe_init
+ if (tc != 0)
+ smvp_copy_vpe_config();
+
+- cpu_set_vpe_id(&cpu_data[ncpu], tc);
+-
+ return ncpu;
+ }
+
+@@ -116,6 +114,49 @@ static void __init smvp_tc_init(unsigned
+ write_tc_c0_tchalt(TCHALT_H);
+ }
+
++static void vsmp_send_ipi_single(int cpu, unsigned int action)
++{
++ int i;
++ unsigned long flags;
++ int vpflags;
++
++#ifdef CONFIG_MIPS_GIC
++ if (gic_present) {
++ mips_smp_send_ipi_single(cpu, action);
++ return;
++ }
++#endif
++ local_irq_save(flags);
++
++ vpflags = dvpe(); /* can't access the other CPU's registers whilst MVPE enabled */
++
++ switch (action) {
++ case SMP_CALL_FUNCTION:
++ i = C_SW1;
++ break;
++
++ case SMP_RESCHEDULE_YOURSELF:
++ default:
++ i = C_SW0;
++ break;
++ }
++
++ /* 1:1 mapping of vpe and tc... */
++ settc(cpu);
++ write_vpe_c0_cause(read_vpe_c0_cause() | i);
++ evpe(vpflags);
++
++ local_irq_restore(flags);
++}
++
++static void vsmp_send_ipi_mask(const struct cpumask *mask, unsigned int action)
++{
++ unsigned int i;
++
++ for_each_cpu(i, mask)
++ vsmp_send_ipi_single(i, action);
++}
++
+ static void vsmp_init_secondary(void)
+ {
+ /* This is Malta specific: IPI,performance and timer interrupts */
+@@ -240,8 +281,8 @@ static void __init vsmp_prepare_cpus(uns
+ }
+
+ const struct plat_smp_ops vsmp_smp_ops = {
+- .send_ipi_single = mips_smp_send_ipi_single,
+- .send_ipi_mask = mips_smp_send_ipi_mask,
++ .send_ipi_single = vsmp_send_ipi_single,
++ .send_ipi_mask = vsmp_send_ipi_mask,
+ .init_secondary = vsmp_init_secondary,
+ .smp_finish = vsmp_smp_finish,
+ .boot_secondary = vsmp_boot_secondary,
+--- a/arch/mips/lantiq/irq.c
++++ b/arch/mips/lantiq/irq.c
+@@ -272,6 +272,47 @@ static void ltq_hw_irq_handler(struct ir
+ ltq_hw_irqdispatch(irq_desc_get_irq(desc) - 2);
+ }
+
++#ifdef CONFIG_MIPS_MT_SMP
++void __init arch_init_ipiirq(int irq, struct irqaction *action)
++{
++ setup_irq(irq, action);
++ irq_set_handler(irq, handle_percpu_irq);
++}
++
++static void ltq_sw0_irqdispatch(void)
++{
++ do_IRQ(MIPS_CPU_IRQ_BASE + MIPS_CPU_IPI_RESCHED_IRQ);
++}
++
++static void ltq_sw1_irqdispatch(void)
++{
++ do_IRQ(MIPS_CPU_IRQ_BASE + MIPS_CPU_IPI_CALL_IRQ);
++}
++static irqreturn_t ipi_resched_interrupt(int irq, void *dev_id)
++{
++ scheduler_ipi();
++ return IRQ_HANDLED;
++}
++
++static irqreturn_t ipi_call_interrupt(int irq, void *dev_id)
++{
++ generic_smp_call_function_interrupt();
++ return IRQ_HANDLED;
++}
++
++static struct irqaction irq_resched = {
++ .handler = ipi_resched_interrupt,
++ .flags = IRQF_PERCPU,
++ .name = "IPI_resched"
++};
++
++static struct irqaction irq_call = {
++ .handler = ipi_call_interrupt,
++ .flags = IRQF_PERCPU,
++ .name = "IPI_call"
++};
++#endif
++
+ asmlinkage void plat_irq_dispatch(void)
+ {
+ unsigned int pending = read_c0_status() & read_c0_cause() & ST0_IM;
+@@ -359,6 +400,17 @@ int __init icu_of_init(struct device_nod
+ (MAX_IM * INT_NUM_IM_OFFSET) + MIPS_CPU_IRQ_CASCADE,
+ &irq_domain_ops, 0);
+
++#if defined(CONFIG_MIPS_MT_SMP)
++ if (cpu_has_vint) {
++ pr_info("Setting up IPI vectored interrupts\n");
++ set_vi_handler(MIPS_CPU_IPI_RESCHED_IRQ, ltq_sw0_irqdispatch);
++ set_vi_handler(MIPS_CPU_IPI_CALL_IRQ, ltq_sw1_irqdispatch);
++ }
++ arch_init_ipiirq(MIPS_CPU_IRQ_BASE + MIPS_CPU_IPI_RESCHED_IRQ,
++ &irq_resched);
++ arch_init_ipiirq(MIPS_CPU_IRQ_BASE + MIPS_CPU_IPI_CALL_IRQ, &irq_call);
++#endif
++
+ #ifndef CONFIG_MIPS_MT_SMP
+ set_c0_status(IE_IRQ0 | IE_IRQ1 | IE_IRQ2 |
+ IE_IRQ3 | IE_IRQ4 | IE_IRQ5);
+--- a/arch/mips/mti-malta/malta-int.c
++++ b/arch/mips/mti-malta/malta-int.c
+@@ -144,6 +144,56 @@ static irqreturn_t corehi_handler(int ir
+ return IRQ_HANDLED;
+ }
+
++#ifdef CONFIG_MIPS_MT_SMP
++
++#define MIPS_CPU_IPI_RESCHED_IRQ 0 /* SW int 0 for resched */
++#define C_RESCHED C_SW0
++#define MIPS_CPU_IPI_CALL_IRQ 1 /* SW int 1 for resched */
++#define C_CALL C_SW1
++static int cpu_ipi_resched_irq, cpu_ipi_call_irq;
++
++static void ipi_resched_dispatch(void)
++{
++ do_IRQ(MIPS_CPU_IRQ_BASE + MIPS_CPU_IPI_RESCHED_IRQ);
++}
++
++static void ipi_call_dispatch(void)
++{
++ do_IRQ(MIPS_CPU_IRQ_BASE + MIPS_CPU_IPI_CALL_IRQ);
++}
++
++static irqreturn_t ipi_resched_interrupt(int irq, void *dev_id)
++{
++#ifdef CONFIG_MIPS_VPE_APSP_API_CMP
++ if (aprp_hook)
++ aprp_hook();
++#endif
++
++ scheduler_ipi();
++
++ return IRQ_HANDLED;
++}
++
++static irqreturn_t ipi_call_interrupt(int irq, void *dev_id)
++{
++ generic_smp_call_function_interrupt();
++
++ return IRQ_HANDLED;
++}
++
++static struct irqaction irq_resched = {
++ .handler = ipi_resched_interrupt,
++ .flags = IRQF_PERCPU,
++ .name = "IPI_resched"
++};
++
++static struct irqaction irq_call = {
++ .handler = ipi_call_interrupt,
++ .flags = IRQF_PERCPU,
++ .name = "IPI_call"
++};
++#endif /* CONFIG_MIPS_MT_SMP */
++
+ static struct irqaction corehi_irqaction = {
+ .handler = corehi_handler,
+ .name = "CoreHi",
+@@ -171,6 +221,12 @@ static msc_irqmap_t msc_eicirqmap[] __in
+
+ static int msc_nr_eicirqs __initdata = ARRAY_SIZE(msc_eicirqmap);
+
++void __init arch_init_ipiirq(int irq, struct irqaction *action)
++{
++ setup_irq(irq, action);
++ irq_set_handler(irq, handle_percpu_irq);
++}
++
+ void __init arch_init_irq(void)
+ {
+ int corehi_irq;
+@@ -216,11 +272,30 @@ void __init arch_init_irq(void)
+
+ if (mips_gic_present()) {
+ corehi_irq = MIPS_CPU_IRQ_BASE + MIPSCPU_INT_COREHI;
+- } else if (cpu_has_veic) {
+- set_vi_handler(MSC01E_INT_COREHI, corehi_irqdispatch);
+- corehi_irq = MSC01E_INT_BASE + MSC01E_INT_COREHI;
+ } else {
+- corehi_irq = MIPS_CPU_IRQ_BASE + MIPSCPU_INT_COREHI;
++#if defined(CONFIG_MIPS_MT_SMP)
++ /* set up ipi interrupts */
++ if (cpu_has_veic) {
++ set_vi_handler (MSC01E_INT_SW0, ipi_resched_dispatch);
++ set_vi_handler (MSC01E_INT_SW1, ipi_call_dispatch);
++ cpu_ipi_resched_irq = MSC01E_INT_SW0;
++ cpu_ipi_call_irq = MSC01E_INT_SW1;
++ } else {
++ cpu_ipi_resched_irq = MIPS_CPU_IRQ_BASE +
++ MIPS_CPU_IPI_RESCHED_IRQ;
++ cpu_ipi_call_irq = MIPS_CPU_IRQ_BASE +
++ MIPS_CPU_IPI_CALL_IRQ;
++ }
++ arch_init_ipiirq(cpu_ipi_resched_irq, &irq_resched);
++ arch_init_ipiirq(cpu_ipi_call_irq, &irq_call);
++#endif
++ if (cpu_has_veic) {
++ set_vi_handler(MSC01E_INT_COREHI,
++ corehi_irqdispatch);
++ corehi_irq = MSC01E_INT_BASE + MSC01E_INT_COREHI;
++ } else {
++ corehi_irq = MIPS_CPU_IRQ_BASE + MIPSCPU_INT_COREHI;
++ }
+ }
+
+ setup_irq(corehi_irq, &corehi_irqaction);