From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932521AbbCCX1O (ORCPT ); Tue, 3 Mar 2015 18:27:14 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:36759 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932254AbbCCXVe (ORCPT ); Tue, 3 Mar 2015 18:21:34 -0500 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Felix Fietkau" , "Ralf Baechle" , linux-mips@linux-mips.org Date: Tue, 03 Mar 2015 22:11:28 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.2 03/24] MIPS: IRQ: Fix disable_irq on CPU IRQs In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.249 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2.68-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Felix Fietkau commit a3e6c1eff54878506b2dddcc202df9cc8180facb upstream. If the irq_chip does not define .irq_disable, any call to disable_irq will defer disabling the IRQ until it fires while marked as disabled. This assumes that the handler function checks for this condition, which handle_percpu_irq does not. In this case, calling disable_irq leads to an IRQ storm, if the interrupt fires while disabled. This optimization is only useful when disabling the IRQ is slow, which is not true for the MIPS CPU IRQ. Disable this optimization by implementing .irq_disable and .irq_enable Signed-off-by: Felix Fietkau Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/8949/ Signed-off-by: Ralf Baechle Signed-off-by: Ben Hutchings --- arch/mips/kernel/irq_cpu.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/arch/mips/kernel/irq_cpu.c +++ b/arch/mips/kernel/irq_cpu.c @@ -56,6 +56,8 @@ static struct irq_chip mips_cpu_irq_cont .irq_mask_ack = mask_mips_irq, .irq_unmask = unmask_mips_irq, .irq_eoi = unmask_mips_irq, + .irq_disable = mask_mips_irq, + .irq_enable = unmask_mips_irq, }; /* @@ -92,6 +94,8 @@ static struct irq_chip mips_mt_cpu_irq_c .irq_mask_ack = mips_mt_cpu_irq_ack, .irq_unmask = unmask_mips_irq, .irq_eoi = unmask_mips_irq, + .irq_disable = mask_mips_irq, + .irq_enable = unmask_mips_irq, }; void __init mips_cpu_irq_init(void)