From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 32557 invoked by alias); 7 Oct 2012 17:24:24 -0000 Received: (qmail 32541 invoked by uid 22791); 7 Oct 2012 17:24:21 -0000 X-SWARE-Spam-Status: No, hits=-2.8 required=5.0 tests=AWL,BAYES_00,KHOP_THREADED X-Spam-Check-By: sourceware.org Received: from hagrid.ecoscentric.com (HELO mail.ecoscentric.com) (212.13.207.197) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Sun, 07 Oct 2012 17:24:15 +0000 Received: from localhost (hagrid.ecoscentric.com [127.0.0.1]) by mail.ecoscentric.com (Postfix) with ESMTP id 16FCE2F78004 for ; Sun, 7 Oct 2012 18:24:14 +0100 (BST) Received: from mail.ecoscentric.com ([127.0.0.1]) by localhost (hagrid.ecoscentric.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 5hXAHUyhVc02; Sun, 7 Oct 2012 18:24:12 +0100 (BST) From: bugzilla-daemon@bugs.ecos.sourceware.org To: ecos-bugs@ecos.sourceware.org Subject: [Bug 1001606] Enable the cache on Kinetis in RAM startup mode X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: eCos X-Bugzilla-Component: HAL X-Bugzilla-Keywords: X-Bugzilla-Severity: enhancement X-Bugzilla-Who: ilijak@siva.com.mk X-Bugzilla-Status: NEEDINFO X-Bugzilla-Priority: low X-Bugzilla-Assigned-To: jifl@ecoscentric.com X-Bugzilla-Target-Milestone: --- X-Bugzilla-Changed-Fields: In-Reply-To: References: X-Bugzilla-URL: http://bugs.ecos.sourceware.org/ Auto-Submitted: auto-generated Content-Type: text/plain; charset="UTF-8" MIME-Version: 1.0 Date: Sun, 07 Oct 2012 17:24:00 -0000 Message-Id: <20121007172412.9080D2F78001@mail.ecoscentric.com> Mailing-List: contact ecos-bugs-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Post: List-Help: , Sender: ecos-bugs-owner@sourceware.org X-SW-Source: 2012/txt/msg01286.txt.bz2 Please do not reply to this email. Use the web interface provided at: http://bugs.ecos.sourceware.org/show_bug.cgi?id=1001606 --- Comment #22 from Ilija Kocho 2012-10-07 18:23:57 BST --- Created an attachment (id=1950) --> (http://bugs.ecos.sourceware.org/attachment.cgi?id=1950) Round-robin bus arbitration for copy-back DDRAM 121007 There is a subtle behaviour (with RAM start-up) when ICACHE is disabled, DCACHE is in copy-back mode. Cache purge or sync gets preempted by code execution. Since the macros for cache syncing and purging contain spin-check of cache status, a deadlock happens, because of perpetual access to DDRAM, that has higher priority than the cache flushing. When ICACHE is enabled there isn't a deadlock, because [after initial misses], the instructions are fetched from ICACHE so code fetches don't compete for DDRAM. The attached code avoids deadlock by introducing round-robin arbitration in case start-up type is RAM and DCACHE uses copy-back scheme. The patch only affects Kinetis variant and is incremental to attachment 1948. Ilija -- Configure bugmail: http://bugs.ecos.sourceware.org/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.