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authorFelipe Balbi <balbi@ti.com>2015-01-02 16:18:54 -0600
committerThomas Gleixner <tglx@linutronix.de>2015-07-22 18:37:42 +0200
commit6ed3464897cc825a75218653c710d673282dfcf8 (patch)
tree1d40b327048a981db84bc7a41862cbd75cb5ba86
parente10fc03c4f89e5191f0ad2a3885d476f498bf131 (diff)
downloadlinux-6ed3464897cc825a75218653c710d673282dfcf8.tar.bz2
irqchip: omap-intc: Improve IRQ handler
As it turns out the current IRQ number will *always* be available from SIR register which renders the reads of PENDING registers as plain unnecessary overhead. In order to catch any situation where SIR reads as zero, we're adding a WARN() to turn it into a very verbose error and users actually report it. With this patch average running time of omap_intc_handle_irq() reduced from about 28.5us to 19.8us as measured by the kernel function profiler. Tested with BeagleBoneBlack Rev A5C. Tested-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Felipe Balbi <balbi@ti.com> Cc: Linux ARM Kernel Mailing List <linux-arm-kernel@lists.infradead.org> Link: http://lkml.kernel.org/r/20150720204910.GH5394@saruman.tx.rr.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
-rw-r--r--drivers/irqchip/irq-omap-intc.c35
1 files changed, 5 insertions, 30 deletions
diff --git a/drivers/irqchip/irq-omap-intc.c b/drivers/irqchip/irq-omap-intc.c
index 6cc0ad57ffab..8587d0f8d8c0 100644
--- a/drivers/irqchip/irq-omap-intc.c
+++ b/drivers/irqchip/irq-omap-intc.c
@@ -330,37 +330,12 @@ 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;
-
- irqnr = intc_readl(INTC_SIR);
- irqnr &= ACTIVEIRQ_MASK;
+ u32 irqnr;
- if (irqnr) {
- handle_domain_irq(domain, irqnr, regs);
- handled_irq = 1;
- }
- } while (irqnr);
-
- /*
- * 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.
- */
- if (!handled_irq)
- omap_ack_irq(NULL);
+ irqnr = intc_readl(INTC_SIR);
+ irqnr &= ACTIVEIRQ_MASK;
+ WARN_ONCE(!irqnr, "Spurious IRQ ?\n");
+ handle_domain_irq(domain, irqnr, regs);
}
void __init omap3_init_irq(void)