From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail177-1.suw61.mandrillapp.com ([198.2.177.1]:58740 "EHLO mail177-1.suw61.mandrillapp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754012AbcCATKH (ORCPT ); Tue, 1 Mar 2016 14:10:07 -0500 Received: from pmta06.mandrill.prod.suw01.rsglab.com (127.0.0.1) by mail177-1.suw61.mandrillapp.com id hqnkgu22rtkk for ; Tue, 1 Mar 2016 19:10:06 +0000 (envelope-from ) From: Subject: Patch "irqchip/omap-intc: Add support for spurious irq handling" has been added to the 4.4-stable tree To: , , , , , , , Cc: , Message-Id: <145685940222238@kroah.com> Date: Tue, 01 Mar 2016 19:10:05 +0000 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled irqchip/omap-intc: Add support for spurious irq handling to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: irqchip-omap-intc-add-support-for-spurious-irq-handling.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From d3b421cd07e4c0d4d6c0bbd55ca169c054fc081d Mon Sep 17 00:00:00 2001 From: Sekhar Nori Date: Tue, 15 Dec 2015 19:56:12 +0530 Subject: irqchip/omap-intc: Add support for spurious irq handling From: Sekhar Nori commit d3b421cd07e4c0d4d6c0bbd55ca169c054fc081d upstream. Under some conditions, irq sorting procedure used by INTC can go wrong resulting in a spurious irq getting reported. If this condition is not handled, it results in endless stream of: unexpected IRQ trap at vector 00 messages from ack_bad_irq() Handle the spurious interrupt condition in omap-intc driver to prevent this. Measurements using kernel function profiler on AM335x EVM running at 720MHz show that after this patch omap_intc_handle_irq() takes about 37.4us against 34us before this patch. Signed-off-by: Sekhar Nori Acked-by: Tony Lindgren Cc: John Ogness Cc: Felipe Balbi Cc: Jason Cooper Cc: Marc Zyngier Link: http://lkml.kernel.org/r/9c78a6db02ac55f7af7371b417b6e414d2c3095b.1450188128.git.nsekhar@ti.com Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman --- drivers/irqchip/irq-omap-intc.c | 27 ++++++++++++++++++++++++++- 1 file changed, 26 insertions(+), 1 deletion(-) --- a/drivers/irqchip/irq-omap-intc.c +++ b/drivers/irqchip/irq-omap-intc.c @@ -47,6 +47,7 @@ #define INTC_ILR0 0x0100 #define ACTIVEIRQ_MASK 0x7f /* omap2/3 active interrupt bits */ +#define SPURIOUSIRQ_MASK (0x1ffffff << 7) #define INTCPS_NR_ILR_REGS 128 #define INTCPS_NR_MIR_REGS 4 @@ -330,11 +331,35 @@ static int __init omap_init_irq(u32 base static asmlinkage void __exception_irq_entry omap_intc_handle_irq(struct pt_regs *regs) { + extern unsigned long irq_err_count; u32 irqnr; irqnr = intc_readl(INTC_SIR); + + /* + * A spurious IRQ can result if interrupt that triggered the + * sorting is no longer active during the sorting (10 INTC + * functional clock cycles after interrupt assertion). Or a + * change in interrupt mask affected the result during sorting + * time. There is no special handling required except ignoring + * the SIR register value just read and retrying. + * See section 6.2.5 of AM335x TRM Literature Number: SPRUH73K + * + * Many a times, a spurious interrupt situation has been fixed + * by adding a flush for the posted write acking the IRQ in + * the device driver. Typically, this is going be the device + * driver whose interrupt was handled just before the spurious + * IRQ occurred. Pay attention to those device drivers if you + * run into hitting the spurious IRQ condition below. + */ + if (unlikely((irqnr & SPURIOUSIRQ_MASK) == SPURIOUSIRQ_MASK)) { + pr_err_once("%s: spurious irq!\n", __func__); + irq_err_count++; + omap_ack_irq(NULL); + return; + } + irqnr &= ACTIVEIRQ_MASK; - WARN_ONCE(!irqnr, "Spurious IRQ ?\n"); handle_domain_irq(domain, irqnr, regs); } Patches currently in stable-queue which might be from nsekhar@ti.com are queue-4.4/irqchip-omap-intc-add-support-for-spurious-irq-handling.patch