Revert "MIPS: Lantiq: Fix cascaded IRQ setup"

This reverts commit 362721c4957dcda7b1fbd45380e7a6617a1d077c which is
commit 6c356eda225e3ee134ed4176b9ae3a76f793f4dd upstream.

It shouldn't have been included in a stable release.

Reported-by: Amit Pundir <amit.pundir@linaro.org>
Cc: Felix Fietkau <nbd@nbd.name>
Cc: John Crispin <john@phrozen.org>
Cc: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 21 insertions, 17 deletions

diff --git a/arch/mips/lantiq/irq.c b/arch/mips/lantiq/irq.c
index 0ddf3698b85d..8ac0e5994ed2 100644
--- a/arch/mips/lantiq/irq.c
+++ b/arch/mips/lantiq/irq.c
@@ -269,11 +269,6 @@ static void ltq_hw5_irqdispatch(void)
 DEFINE_HWx_IRQDISPATCH(5)
 #endif
 
-static void ltq_hw_irq_handler(struct irq_desc *desc)
-{
-        ltq_hw_irqdispatch(irq_desc_get_irq(desc) - 2);
-}
-
 #ifdef CONFIG_MIPS_MT_SMP
 void __init arch_init_ipiirq(int irq, struct irqaction *action)
 {
@@ -318,19 +313,23 @@ static struct irqaction irq_call = {
 asmlinkage void plat_irq_dispatch(void)
 {
         unsigned int pending = read_c0_status() & read_c0_cause() & ST0_IM;
-        int irq;
-
-        if (!pending) {
-                spurious_interrupt();
-                return;
+        unsigned int i;
+
+        if ((MIPS_CPU_TIMER_IRQ == 7) && (pending & CAUSEF_IP7)) {
+                do_IRQ(MIPS_CPU_TIMER_IRQ);
+                goto out;
+        } else {
+                for (i = 0; i < MAX_IM; i++) {
+                        if (pending & (CAUSEF_IP2 << i)) {
+                                ltq_hw_irqdispatch(i);
+                                goto out;
+                        }
+                }
         }
+        pr_alert("Spurious IRQ: CAUSE=0x%08x\n", read_c0_status());
 
-        pending >>= CAUSEB_IP;
-        while (pending) {
-                irq = fls(pending) - 1;
-                do_IRQ(MIPS_CPU_IRQ_BASE + irq);
-                pending &= ~BIT(irq);
-        }
+out:
+        return;
 }
 
 static int icu_map(struct irq_domain *d, unsigned int irq, irq_hw_number_t hw)
@@ -355,6 +354,11 @@ static const struct irq_domain_ops irq_domain_ops = {
         .map = icu_map,
 };
 
+static struct irqaction cascade = {
+        .handler = no_action,
+        .name = "cascade",
+};
+
 int __init icu_of_init(struct device_node *node, struct device_node *parent)
 {
         struct device_node *eiu_node;
@@ -386,7 +390,7 @@ int __init icu_of_init(struct device_node *node, struct device_node *parent)
         mips_cpu_irq_init();
 
         for (i = 0; i < MAX_IM; i++)
-                irq_set_chained_handler(i + 2, ltq_hw_irq_handler);
+                setup_irq(i + 2, &cascade);
 
         if (cpu_has_vint) {
                 pr_info("Setting up vectored interrupts\n");