From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755692AbdHYRX2 (ORCPT ); Fri, 25 Aug 2017 13:23:28 -0400 Received: from smtprelay.synopsys.com ([198.182.47.9]:42995 "EHLO smtprelay.synopsys.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753418AbdHYRX1 (ORCPT ); Fri, 25 Aug 2017 13:23:27 -0400 From: Alexey Brodkin To: Vineet Gupta CC: Eugeniy Paltsev , "linux-kernel@vger.kernel.org" , "linux-snps-arc@lists.infradead.org" Subject: Re: [PATCHi v2] arc: Mask individual IRQ lines during core INTC init Thread-Topic: [PATCHi v2] arc: Mask individual IRQ lines during core INTC init Thread-Index: AQHTHa2gyduNY6cjQU61lN/WOukMsaKVLhiAgAAChwA= Date: Fri, 25 Aug 2017 17:22:41 +0000 Message-ID: <1503681760.10779.75.camel@synopsys.com> References: <1503670961-16781-1-git-send-email-abrodkin@synopsys.com> In-Reply-To: Accept-Language: en-US, ru-RU Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.121.8.71] Content-Type: text/plain; charset="utf-8" Content-ID: MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by nfs id v7PHNXBx011121 Hi Vineet, On Fri, 2017-08-25 at 10:13 -0700, Vineet Gupta wrote: > On 08/25/2017 07:22 AM, Alexey Brodkin wrote: > > > > From: Alexey Brodkin > > > > ARC cores on reset have all interrupt lines of built-in INTC enabled. > > Which means once we globally enable interrupts (very early on boot) > > faulty hardware blocks may trigger an interrupt that Linux kernel > > cannot handle yet as corresponding handler is not yet installed. > > > > In that case system falls in "interrupt storm" and basically never > > does anything useful except entering and exiting generic IRQ handling > > code. > > > > One real example of that kind of problematic hardware is DW GMAC which > > also has interrupts enabled on reset and if Ethernet PHY informs GMAC > > about link state, GMAC immediately reports that upstream to ARC core > > and here we are. > > > > Now with that change we mask all individual IRQ lines making entire > > system more fool-proof. > > > > [This patch was motivated by Adaptrum platform support] > > > > Signed-off-by: Alexey Brodkin > > Cc: Eugeniy Paltsev > > Tested-by: Alexandru Gagniuc > > Signed-off-by: Vineet Gupta > > v1 was merged in mainline this week - please provide a fixup patch on top of  > mainline / for-curr ! Ooops, didn't see that. Will do shortly. -Alexey