From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 8977 invoked by alias); 1 Nov 2013 17:20:51 -0000 Mailing-List: contact ecos-discuss-help@ecos.sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: ecos-discuss-owner@ecos.sourceware.org Received: (qmail 8960 invoked by uid 89); 1 Nov 2013 17:20:50 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.2 required=5.0 tests=AWL,BAYES_00 autolearn=ham version=3.3.2 X-HELO: mail.carallon.com Received: from mail.carallon.com (HELO mail.carallon.com) (95.177.28.122) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Fri, 01 Nov 2013 17:20:50 +0000 X-MDAV-Result: clean X-MDAV-Processed: mail.carallon.com, Fri, 01 Nov 2013 17:20:48 +0000 Received: from [172.20.1.41] by mail.carallon.com (Cipher TLSv1:-SHA:128) (MDaemon PRO v13.6.0) with ESMTP id md50001443476.msg for ; Fri, 01 Nov 2013 17:20:47 +0000 X-Spam-Processed: mail.carallon.com, Fri, 01 Nov 2013 17:20:47 +0000 (not processed: message from trusted or authenticated source) X-MDRemoteIP: 172.20.1.41 X-Return-Path: andrewp@carallon.com X-Envelope-From: andrewp@carallon.com X-MDaemon-Deliver-To: ecos-discuss@ecos.sourceware.org Message-ID: <5273E2EE.3010908@carallon.com> Date: Fri, 01 Nov 2013 17:20:00 -0000 From: Andrew Parlane User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:24.0) Gecko/20100101 Thunderbird/24.1.0 MIME-Version: 1.0 To: Nick Garnett , ecos-discuss@ecos.sourceware.org References: <52729021.3080205@carallon.com> <5273DFAE.1080000@calivar.com> In-Reply-To: <5273DFAE.1080000@calivar.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [ECOS] Spurious interrupt on ARM. X-SW-Source: 2013-11/txt/msg00005.txt.bz2 Sorry, I should have been a bit more clear. First we skip the ISR by jumping to the spurious_IRQ label, and then we switch stacks if necessary, then we have (line numbers may vary): 941 // The return value from the handler (in r0) will indicate whether a 942 // DSR is to be posted. Pass this together with a pointer to the 943 // interrupt object we have just used to the interrupt tidy up routine. 944 945 // don't run this for spurious interrupts! 946 cmp v1,#CYGNUM_HAL_INTERRUPT_NONE 947 beq 17f 948 ldr r1,.hal_interrupt_objects 949 ldr r1,[r1,v1,lsl #2] 950 mov r2,v6 // register frame 951 952 THUMB_MODE(r3,10) 953 954 bl interrupt_end // post any bottom layer handler 955 // threads and call scheduler 956 ARM_MODE(r1,10) 957 17: So it compares the result of hal_IRQ_handler (stored in v1) with CYGNUM_HAL_INTERRUPT_NONE, and jumps forwards to label 17: which is after interrupt_end. if it was a spurious IRQ. Andrew On 01/11/2013 17:06, Nick Garnett wrote: > > On 31/10/13 17:15, Andrew Parlane wrote: >> Looking at hal/arm/arch/current/src/vectors.S in IRQ: >> >> We increment the scheduler lock and decrement it again in interrupt_end. >> >> In the case of there being a spurious interrupt, we don't call >> interrupt_end, and so the scheduler never gets decremented. >> >> Am I missing something here? > interrupt_end() does get called. A spurious interrupt only causes the > code to skip calling an ISR by jumping to the spurious_IRQ label. From > there it follows the same code path and will call interrupt_end() as normal. > -- Before posting, please read the FAQ: http://ecos.sourceware.org/fom/ecos and search the list archive: http://ecos.sourceware.org/ml/ecos-discuss