Commit-ID: 6ed3464897cc825a75218653c710d673282dfcf8
Gitweb: http://git.kernel.org/tip/6ed3464897cc825a75218653c710d673282dfcf8
Author: Felipe Balbi <balbi@xxxxxx>
AuthorDate: Fri, 2 Jan 2015 16:18:54 -0600
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Wed, 22 Jul 2015 18:37:42 +0200
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@xxxxxxxxxxx>
Signed-off-by: Felipe Balbi <balbi@xxxxxx>
Cc: Linux ARM Kernel Mailing List <linux-arm-kernel@xxxxxxxxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/20150720204910.GH5394@xxxxxxxxxxxxxxxxx
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
drivers/irqchip/irq-omap-intc.c | 35 +++++------------------------------
1 file changed, 5 insertions(+), 30 deletions(-)
diff --git a/drivers/irqchip/irq-omap-intc.c b/drivers/irqchip/irq-omap-intc.c
index 6cc0ad5..8587d0f 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)
--
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