From: Felipe Balbi <balbi@ti.com> To: Thomas Gleixner <tglx@linutronix.de>, Jason Cooper <jason@lakedaemon.net> Cc: Linux OMAP Mailing List <linux-omap@vger.kernel.org>, Tony Lindgren <tony@atomide.com>, Aaro Koskinen <aaro.koskinen@iki.fi>, Linux ARM Kernel Mailing List <linux-arm-kernel@lists.infradead.org>, Felipe Balbi <balbi@ti.com> Subject: [PATCH] irqchip: omap-intc: improve IRQ handler Date: Fri, 2 Jan 2015 12:47:13 -0600 [thread overview] Message-ID: <1420224433-27001-1-git-send-email-balbi@ti.com> (raw) 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. Signed-off-by: Felipe Balbi <balbi@ti.com> --- Before applying, it would be very nice to get reports from other folks on different platforms, specially OMAP2/3 ones which I don't have (easy) access. 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 28718d3..a2da6d5 100644 --- a/drivers/irqchip/irq-omap-intc.c +++ b/drivers/irqchip/irq-omap-intc.c @@ -315,37 +315,12 @@ 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(!irqnr, "Spuriour IRQ ?\n"); + handle_domain_irq(domain, irqnr, regs); } void __init omap2_init_irq(void) -- 2.2.0
WARNING: multiple messages have this Message-ID (diff)
From: balbi@ti.com (Felipe Balbi) To: linux-arm-kernel@lists.infradead.org Subject: [PATCH] irqchip: omap-intc: improve IRQ handler Date: Fri, 2 Jan 2015 12:47:13 -0600 [thread overview] Message-ID: <1420224433-27001-1-git-send-email-balbi@ti.com> (raw) 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. Signed-off-by: Felipe Balbi <balbi@ti.com> --- Before applying, it would be very nice to get reports from other folks on different platforms, specially OMAP2/3 ones which I don't have (easy) access. 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 28718d3..a2da6d5 100644 --- a/drivers/irqchip/irq-omap-intc.c +++ b/drivers/irqchip/irq-omap-intc.c @@ -315,37 +315,12 @@ 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(!irqnr, "Spuriour IRQ ?\n"); + handle_domain_irq(domain, irqnr, regs); } void __init omap2_init_irq(void) -- 2.2.0
next reply other threads:[~2015-01-02 18:48 UTC|newest] Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top 2015-01-02 18:47 Felipe Balbi [this message] 2015-01-02 18:47 ` [PATCH] irqchip: omap-intc: improve IRQ handler Felipe Balbi 2015-01-02 21:32 ` Tony Lindgren 2015-01-02 21:32 ` Tony Lindgren 2015-01-02 21:39 ` Felipe Balbi 2015-01-02 21:39 ` Felipe Balbi 2015-01-02 22:18 ` [PATCH v2] " Felipe Balbi 2015-01-02 22:18 ` Felipe Balbi 2015-01-19 21:34 ` [PATCH] " Tony Lindgren 2015-01-19 21:34 ` Tony Lindgren 2015-07-15 8:15 ` Tony Lindgren 2015-07-15 8:15 ` Tony Lindgren 2015-07-15 12:36 ` Thomas Gleixner 2015-07-15 12:36 ` Thomas Gleixner 2015-07-20 16:44 ` Felipe Balbi 2015-07-20 16:44 ` Felipe Balbi
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