From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 31328C432BE for ; Thu, 2 Sep 2021 10:24:06 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id D1060610A1 for ; Thu, 2 Sep 2021 10:24:05 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org D1060610A1 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ilande.co.uk Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=nongnu.org Received: from localhost ([::1]:51876 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mLjt7-0000Pm-0g for qemu-devel@archiver.kernel.org; Thu, 02 Sep 2021 06:24:05 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:34644) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mLjrb-0005dj-6O for qemu-devel@nongnu.org; Thu, 02 Sep 2021 06:22:31 -0400 Received: from mail.ilande.co.uk ([2001:41c9:1:41f::167]:57630 helo=mail.default.ilande.bv.iomart.io) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mLjrY-0001O9-Ke for qemu-devel@nongnu.org; Thu, 02 Sep 2021 06:22:29 -0400 Received: from host86-133-17-27.range86-133.btcentralplus.com ([86.133.17.27] helo=kentang.home) by mail.default.ilande.bv.iomart.io with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1mLjr7-0000t5-Fy; Thu, 02 Sep 2021 11:22:06 +0100 From: Mark Cave-Ayland To: qemu-devel@nongnu.org, laurent@vivier.eu Date: Thu, 2 Sep 2021 11:21:58 +0100 Message-Id: <20210902102205.7554-3-mark.cave-ayland@ilande.co.uk> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20210902102205.7554-1-mark.cave-ayland@ilande.co.uk> References: <20210902102205.7554-1-mark.cave-ayland@ilande.co.uk> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SA-Exim-Connect-IP: 86.133.17.27 X-SA-Exim-Mail-From: mark.cave-ayland@ilande.co.uk Subject: [PATCH v2 2/9] escc: reset register values to zero in escc_reset() X-SA-Exim-Version: 4.2.1 (built Wed, 08 May 2019 21:11:16 +0000) X-SA-Exim-Scanned: Yes (on mail.default.ilande.bv.iomart.io) Received-SPF: pass client-ip=2001:41c9:1:41f::167; envelope-from=mark.cave-ayland@ilande.co.uk; helo=mail.default.ilande.bv.iomart.io X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" This is to ensure that a device reset always returns the ESCC to a known state. Note that this is currently redundant with the same code in escc_reset_chn() but that will change shortly. Signed-off-by: Mark Cave-Ayland --- hw/char/escc.c | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-) diff --git a/hw/char/escc.c b/hw/char/escc.c index c87ecd59d8..b0d3b92dc1 100644 --- a/hw/char/escc.c +++ b/hw/char/escc.c @@ -300,9 +300,24 @@ static void escc_reset_chn(ESCCChannelState *s) static void escc_reset(DeviceState *d) { ESCCState *s = ESCC(d); + int i, j; - escc_reset_chn(&s->chn[0]); - escc_reset_chn(&s->chn[1]); + for (i = 0; i < 2; i++) { + ESCCChannelState *cs = &s->chn[i]; + + /* + * According to the ESCC datasheet "Miscellaneous Questions" section + * on page 384, the values of the ESCC registers are not guaranteed on + * power-on until an explicit hardware or software reset has been + * issued. For now we zero the registers so that a device reset always + * returns the emulated device to a fixed state. + */ + for (j = 0; j < ESCC_SERIAL_REGS; j++) { + cs->rregs[j] = 0; + cs->wregs[j] = 0; + } + escc_reset_chn(cs); + } } static inline void set_rxint(ESCCChannelState *s) -- 2.20.1