From patchwork Sun Dec 16 23:56:26 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Ogilvie X-Patchwork-Id: 206762 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 2144C2C00A8 for ; Mon, 17 Dec 2012 12:12:51 +1100 (EST) Received: from localhost ([::1]:35098 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TkO6J-0005fr-Sh for incoming@patchwork.ozlabs.org; Sun, 16 Dec 2012 18:58:31 -0500 Received: from eggs.gnu.org ([208.118.235.92]:60720) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TkO4k-0002Kf-TK for qemu-devel@nongnu.org; Sun, 16 Dec 2012 18:56:57 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1TkO4h-0007Hw-UM for qemu-devel@nongnu.org; Sun, 16 Dec 2012 18:56:54 -0500 Received: from qmta07.emeryville.ca.mail.comcast.net ([76.96.30.64]:44288) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TkO4h-0007Ho-8a for qemu-devel@nongnu.org; Sun, 16 Dec 2012 18:56:51 -0500 Received: from omta06.emeryville.ca.mail.comcast.net ([76.96.30.51]) by qmta07.emeryville.ca.mail.comcast.net with comcast id cNwF1k00616AWCUA7Pwp6d; Sun, 16 Dec 2012 23:56:49 +0000 Received: from mmogilvi.homeip.net ([75.70.117.91]) by omta06.emeryville.ca.mail.comcast.net with comcast id cPwo1k00f1yPlfP8SPwpu7; Sun, 16 Dec 2012 23:56:49 +0000 Received: by mmogilvi.homeip.net (Postfix, from userid 501) id 82B7E1E9601C; Sun, 16 Dec 2012 16:56:48 -0700 (MST) From: Matthew Ogilvie To: qemu-devel@nongnu.org Date: Sun, 16 Dec 2012 16:56:26 -0700 Message-Id: <1355702189-6994-8-git-send-email-mmogilvi_qemu@miniinfo.net> X-Mailer: git-send-email 1.7.10.2.484.gcd07cc5 In-Reply-To: <1355702189-6994-1-git-send-email-mmogilvi_qemu@miniinfo.net> References: <1355702189-6994-1-git-send-email-mmogilvi_qemu@miniinfo.net> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=comcast.net; s=q20121106; t=1355702209; bh=eitwlOlZ5jHuFLQud+gz8pG7hGyB7GGQNmHdytpy3ho=; h=Received:Received:Received:From:To:Subject:Date:Message-Id; b=dPxr82eovMFi05/Cj1mmf7sTXIas74BVUq9TEfu8b6YERD3OHvWwPbrA+XQoMbYcP QH1SXGIgiBntaPueNV2QzNe/qMIiOT+FWa1/qF1HBKlTPbHvSLdkMvKTvUvIsigzNi 6xwCzn5Wi57gW8lMfYfQPElbgwcE6q+H+UuLW1Pp+V5SmYiD2q8kjz46H0yWdEDAlY 0SHVg4HarDi+uvAr4VzpkW04pyDgcsFoA3Y5ZsqlfW6hCnPnFg47IWxf6+PeB3rONS tm4MrajjK0GqG7rz1o58U8cTFGhxpbGocRT49GMcDop+ZLR91LLX4DTPkgBdSHtgZe jLk8B0XcxMEGA== X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 76.96.30.64 Cc: "Maciej W. Rozycki" , Jan Kiszka , Matthew Ogilvie , Gleb Natapov Subject: [Qemu-devel] [PATCH v8 07/10] i8259: refactor pic_set_irq level logic X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org No change in functionality. Clarify that the only difference between level triggered and edge triggered interrupts is on the leading edge. Signed-off-by: Matthew Ogilvie --- hw/i8259.c | 26 +++++++++----------------- 1 file changed, 9 insertions(+), 17 deletions(-) diff --git a/hw/i8259.c b/hw/i8259.c index 95587cd..9b2ec40 100644 --- a/hw/i8259.c +++ b/hw/i8259.c @@ -140,26 +140,18 @@ static void pic_set_irq(void *opaque, int irq, int level) } #endif - if (s->elcr & mask) { - /* level triggered */ - if (level) { + if (level) { + if ((s->last_irr & mask) == 0 || /* edge for edge triggered */ + (s->elcr & mask)) { /* or level triggered */ s->irr |= mask; - s->last_irr |= mask; - } else { - s->irr &= ~mask; - s->last_irr &= ~mask; } + s->last_irr |= mask; } else { - /* edge triggered */ - if (level) { - if ((s->last_irr & mask) == 0) { - s->irr |= mask; - } - s->last_irr |= mask; - } else { - s->irr &= ~mask; - s->last_irr &= ~mask; - } + /* Dropping level clears the interrupt regardless of edge trigger + * vs level trigger. + */ + s->irr &= ~mask; + s->last_irr &= ~mask; } pic_update_irq(s); }