These changes are the raw update to linux-4.4.6-rt14. Kernel sources

[kvmfornfv.git] / kernel / drivers / irqchip / irq-omap-intc.c

diff --git a/kernel/drivers/irqchip/irq-omap-intc.c b/kernel/drivers/irqchip/irq-omap-intc.c
index a569c6d..f6cb1b8 100644 (file)
--- a/kernel/drivers/irqchip/irq-omap-intc.c
+++ b/kernel/drivers/irqchip/irq-omap-intc.c
@@ -17,13 +17,12 @@
 #include <linux/io.h>
 
 #include <asm/exception.h>
+#include <linux/irqchip.h>
 #include <linux/irqdomain.h>
 #include <linux/of.h>
 #include <linux/of_address.h>
 #include <linux/of_irq.h>
 
-#include "irqchip.h"
-
 /* Define these here for now until we drop all board-files */
 #define OMAP24XX_IC_BASE       0x480fe000
 #define OMAP34XX_IC_BASE       0x48200000
@@ -48,6 +47,7 @@
 #define INTC_ILR0              0x0100
 
 #define ACTIVEIRQ_MASK         0x7f    /* omap2/3 active interrupt bits */
+#define SPURIOUSIRQ_MASK       (0x1ffffff << 7)
 #define INTCPS_NR_ILR_REGS     128
 #define INTCPS_NR_MIR_REGS     4
 
@@ -331,37 +331,36 @@ static int __init omap_init_irq(u32 base, struct device_node *node)
 static asmlinkage void __exception_irq_entry
 omap_intc_handle_irq(struct pt_regs *regs)
 {
-       u32 irqnr = 0;
-       int handled_irq = 0;
-       int i;
-
-       do {
-               for (i = 0; i < omap_nr_pending; i++) {
-                       irqnr = intc_readl(INTC_PENDING_IRQ0 + (0x20 * i));
-                       if (irqnr)
-                               goto out;
-               }
-
-out:
-               if (!irqnr)
-                       break;
+       extern unsigned long irq_err_count;
+       u32 irqnr;
 
-               irqnr = intc_readl(INTC_SIR);
-               irqnr &= ACTIVEIRQ_MASK;
-
-               if (irqnr) {
-                       handle_domain_irq(domain, irqnr, regs);
-                       handled_irq = 1;
-               }
-       } while (irqnr);
+       irqnr = intc_readl(INTC_SIR);
 
        /*
-        * If an irq is masked or deasserted while active, we will
-        * keep ending up here with no irq handled. So remove it from
-        * the INTC with an ack.
+        * A spurious IRQ can result if interrupt that triggered the
+        * sorting is no longer active during the sorting (10 INTC
+        * functional clock cycles after interrupt assertion). Or a
+        * change in interrupt mask affected the result during sorting
+        * time. There is no special handling required except ignoring
+        * the SIR register value just read and retrying.
+        * See section 6.2.5 of AM335x TRM Literature Number: SPRUH73K
+        *
+        * Many a times, a spurious interrupt situation has been fixed
+        * by adding a flush for the posted write acking the IRQ in
+        * the device driver. Typically, this is going be the device
+        * driver whose interrupt was handled just before the spurious
+        * IRQ occurred. Pay attention to those device drivers if you
+        * run into hitting the spurious IRQ condition below.
         */
-       if (!handled_irq)
+       if (unlikely((irqnr & SPURIOUSIRQ_MASK) == SPURIOUSIRQ_MASK)) {
+               pr_err_once("%s: spurious irq!\n", __func__);
+               irq_err_count++;
                omap_ack_irq(NULL);
+               return;
+       }
+
+       irqnr &= ACTIVEIRQ_MASK;
+       handle_domain_irq(domain, irqnr, regs);
 }
 
 void __init omap3_init_irq(void)