From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755806AbbGTQqj (ORCPT ); Mon, 20 Jul 2015 12:46:39 -0400 Received: from bear.ext.ti.com ([192.94.94.41]:33000 "EHLO bear.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752782AbbGTQqi (ORCPT ); Mon, 20 Jul 2015 12:46:38 -0400 From: Felipe Balbi To: Thomas Gleixner CC: Tony Lindgren , Linux OMAP Mailing List , Linux ARM Kernel Mailing List , Linux Kernel Mailing List , Felipe Balbi Subject: [PATCH RESEND] irqchip: omap-intc: improve IRQ handler Date: Mon, 20 Jul 2015 11:45:59 -0500 Message-ID: <1437410759-4945-1-git-send-email-balbi@ti.com> X-Mailer: git-send-email 2.4.4 MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 Signed-off-by: Felipe Balbi --- 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 a569c6dbd1d1..0706db624213 100644 --- a/drivers/irqchip/irq-omap-intc.c +++ b/drivers/irqchip/irq-omap-intc.c @@ -331,37 +331,12 @@ 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, "Spurious IRQ ?\n"); + handle_domain_irq(domain, irqnr, regs); } void __init omap3_init_irq(void) -- 2.4.4