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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no 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 950D3C432BE for ; Sun, 29 Aug 2021 13:21:42 +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 4FD076023F for ; Sun, 29 Aug 2021 13:21:42 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 4FD076023F Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linaro.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=nongnu.org Received: from localhost ([::1]:59974 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mKKkn-0001xh-Gx for qemu-devel@archiver.kernel.org; Sun, 29 Aug 2021 09:21:41 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:58970) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mKKjx-0001GM-Jp for qemu-devel@nongnu.org; Sun, 29 Aug 2021 09:20:49 -0400 Received: from mail-ed1-x52e.google.com ([2a00:1450:4864:20::52e]:34383) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1mKKjw-0008Nw-1A for qemu-devel@nongnu.org; Sun, 29 Aug 2021 09:20:49 -0400 Received: by mail-ed1-x52e.google.com with SMTP id i6so17378463edu.1 for ; Sun, 29 Aug 2021 06:20:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=oobGl3fCn1XFnIgexGn4COkTfceanNK7J8aQ0oxJor4=; b=shkulshdouG0rfeF8DXzgvs5aqnqbGDf9KzmeDcaEAbgOdNSEfPDo4vqmOjPuj5qlC h2pabprk+k1bkui+DMnSAGb/2kLCBGkGnbce3ZsozzzEFNb+SzP7qsCvXjg2DrFfco0m loqgfUS9gBGurVX2UEsnmu3/IeKI9TeCYoDcmcmTQrZZtIbkPldFuf035fIUv1elYqjb XZ1nzjVKTfuqK6yZ6TBDz/cZEZBdRXypFgDBKyrJrI5Aug6KfcBH+BY6xbSnOtL0KUz9 nrICUEpxcxBjArC5gP1UbikvlXBzuWn/1lCEGGwWJ0f16XLI/WDUEiWBF7rdJgLy10qN vGLg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=oobGl3fCn1XFnIgexGn4COkTfceanNK7J8aQ0oxJor4=; b=Mu6NRDtq5it4ZQ7fSQbrIfddBEZaBUeOe5PKr9P0WoBQXV1CzONDjvOrfyb2GdmFWj kkCFBOgxPl6lmqKkMg/knzjSKXyvQBdSbg7biXR60258PYHMCac8fynq0oxDuSN9hL47 G7ptonNSjWTw190xgvFrIApp7y63w8xP9diIgY+wE4RVvDH7Tl8bf28blBeLclvX45VF GhvCvdTabRaCp+qT+fqwwoqCFSIa+IFI/npOU3Q+gMfLs9aSrFn9EI5T+nnLSrFQ0cUE WWXB0IeD7vPGTcyOiRxkz6+MdNhg32d1B5D7nvrHZ7k5mdzmHxoaxsYd3eTezvdGrxNP wIBw== X-Gm-Message-State: AOAM530lykjN1Vmp2Fq1ptaM8vuQTtQDY4/3OwpLTNx30H75KMW8A5UP lyX+KVjONiKau5UBEBqmjeUGdoTZu8wzKMzDleLKfg== X-Google-Smtp-Source: ABdhPJwyzX2s/Kg0uPioOlIRgYFi6z+ESxF7wRQ07ruoCFmtyJge6R91DcigjJnOQk9HSM5eB97ntUAH6Nv74nZi060= X-Received: by 2002:a05:6402:157:: with SMTP id s23mr19222294edu.36.1630243246602; Sun, 29 Aug 2021 06:20:46 -0700 (PDT) MIME-Version: 1.0 References: <20210829100103.1950-1-mark.cave-ayland@ilande.co.uk> In-Reply-To: <20210829100103.1950-1-mark.cave-ayland@ilande.co.uk> From: Peter Maydell Date: Sun, 29 Aug 2021 14:19:58 +0100 Message-ID: Subject: Re: [PATCH 0/3] escc: fix R_STATUS when SDLC mode is enabled To: Mark Cave-Ayland Content-Type: text/plain; charset="UTF-8" Received-SPF: pass client-ip=2a00:1450:4864:20::52e; envelope-from=peter.maydell@linaro.org; helo=mail-ed1-x52e.google.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, 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: , Cc: QEMU Developers , Laurent Vivier Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Sun, 29 Aug 2021 at 11:05, Mark Cave-Ayland wrote: > > Here is another small set of ESCC fixes from my attempts to boot MacOS on the q800 > machine. > > When MacOS loads the OpenTransport extension on boot it attempts to enable > SDLC mode on the ESCC. QEMU's emulation doesn't support SDLC mode, but without > these fixes the active low STATUS_SYNC bit in R_STATUS is continually > asserted causing the extension to hang on startup as it believe it is constantly > receiving LocalTalk responses during its initial negotiation phase. The ESCC data sheet is the first one I've ever encountered that includes a multiple-choice test on features of the device ("ESCC Questions and Answers" on pages 385/386: http://www.zilog.com/docs/serial/scc_escc_um.pdf ) :-) -- PMM