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Diffstat (limited to 'kernel/drivers/irqchip/irq-omap-intc.c')
-rw-r--r--kernel/drivers/irqchip/irq-omap-intc.c55
1 files changed, 27 insertions, 28 deletions
diff --git a/kernel/drivers/irqchip/irq-omap-intc.c b/kernel/drivers/irqchip/irq-omap-intc.c
index a569c6dbd..f6cb1b8bb 100644
--- 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+ * sorting is no longer active during the sorting (10 INTC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)