From patchwork Mon Jul 20 20:49:10 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Felipe Balbi X-Patchwork-Id: 6830601 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 09E88C05AC for ; Mon, 20 Jul 2015 20:51:33 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 24E0A20601 for ; Mon, 20 Jul 2015 20:51:32 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 1145D205F3 for ; Mon, 20 Jul 2015 20:51:31 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1ZHI0R-0001Gx-RT; Mon, 20 Jul 2015 20:49:47 +0000 Received: from devils.ext.ti.com ([198.47.26.153]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1ZHI0O-000179-7P for linux-arm-kernel@lists.infradead.org; Mon, 20 Jul 2015 20:49:44 +0000 Received: from dflxv15.itg.ti.com ([128.247.5.124]) by devils.ext.ti.com (8.13.7/8.13.7) with ESMTP id t6KKnB5Q012862; Mon, 20 Jul 2015 15:49:11 -0500 Received: from DFLE72.ent.ti.com (dfle72.ent.ti.com [128.247.5.109]) by dflxv15.itg.ti.com (8.14.3/8.13.8) with ESMTP id t6KKnBmg029697; Mon, 20 Jul 2015 15:49:11 -0500 Received: from dflp33.itg.ti.com (10.64.6.16) by DFLE72.ent.ti.com (128.247.5.109) with Microsoft SMTP Server id 14.3.224.2; Mon, 20 Jul 2015 15:48:39 -0500 Received: from localhost (ileax41-snat.itg.ti.com [10.172.224.153]) by dflp33.itg.ti.com (8.14.3/8.13.8) with ESMTP id t6KKnA52008336; Mon, 20 Jul 2015 15:49:10 -0500 Date: Mon, 20 Jul 2015 15:49:10 -0500 From: Felipe Balbi To: Thomas Gleixner Subject: Re: [PATCH RESEND] irqchip: omap-intc: improve IRQ handler Message-ID: <20150720204910.GH5394@saruman.tx.rr.com> References: <1437410759-4945-1-git-send-email-balbi@ti.com> MIME-Version: 1.0 In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20150720_134944_360146_A976BF03 X-CRM114-Status: GOOD ( 19.46 ) X-Spam-Score: -8.1 (--------) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: balbi@ti.com Cc: Tony Lindgren , Linux OMAP Mailing List , Linux ARM Kernel Mailing List , Felipe Balbi , Linux Kernel Mailing List Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-5.4 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP On Mon, Jul 20, 2015 at 10:44:08PM +0200, Thomas Gleixner wrote: > On Mon, 20 Jul 2015, Felipe Balbi wrote: > > + irqnr = intc_readl(INTC_SIR); > > + irqnr &= ACTIVEIRQ_MASK; > > + WARN(!irqnr, "Spurious IRQ ?\n"); > > Shouldn't that be WARN_ONCE? Sure, why not ? 8<-------------------------------------------------------------------- From a71590d725e54b888db278de6c278d2a106fc76d Mon Sep 17 00:00:00 2001 From: Felipe Balbi Date: Fri, 2 Jan 2015 16:18:54 -0600 Subject: [PATCH RESEND v2] 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 Signed-off-by: Felipe Balbi --- Changes from V1: - replace WARN() with WARN_ONCE() 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..e15f10746310 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_ONCE(!irqnr, "Spurious IRQ ?\n"); + handle_domain_irq(domain, irqnr, regs); } void __init omap3_init_irq(void)