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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 62DB5C00A5A for ; Thu, 19 Jan 2023 13:33:59 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pIV1B-0004sU-9A; Thu, 19 Jan 2023 08:31:49 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pIV13-0004P8-Im for qemu-devel@nongnu.org; Thu, 19 Jan 2023 08:31:41 -0500 Received: from mail-pj1-x102f.google.com ([2607:f8b0:4864:20::102f]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1pIV11-0000cl-KH for qemu-devel@nongnu.org; Thu, 19 Jan 2023 08:31:41 -0500 Received: by mail-pj1-x102f.google.com with SMTP id o13so2408052pjg.2 for ; Thu, 19 Jan 2023 05:31:39 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=xCMuQOEvhJPcTcEOSP3gcDTwP3FmeI54dDpngbTo6ww=; b=u3dlXLlG+9lIhC7ouw6M1f00hvuyEdiV2Me6QddCh/4gKc9fhSuy8gObHjG1H3ILDs 9UGKSPaLi/MGBNVfv5yjiBUT1KcynCNmQLhnuS4LBej9e8NWX2RmRqQ3l5w7SwAA7E17 byCcruZ5Othd0hfEbWtm9UveBkkCXGG8zNDQDyHFbjDGOaPeNit91MlSmGhmkScmFfIX SZ05tJI5IasILRxAvFOzOmfETypaQW8P7ciuDvW76LILUC2j8M1srfHMjjnkrOQxvTQa pSGLMg4K1ASBw4cK5JGHnalbBcUoigPVVlG2QSiDNVA/sg2vBVbfE2C8Myi2ycIUcl11 +l5g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=xCMuQOEvhJPcTcEOSP3gcDTwP3FmeI54dDpngbTo6ww=; b=KF6fl3+FiUTArmRGPSGcWvMxzMTFsSqGaZWEipyZs4YizfWHwWVRZd4PA/M6oFSCs/ EPedPI7BOZnJgskIlpABwZ3eDUEkgliX3yUo1FvBPFWqPIaCBSDE8j5e3lxCp5ZCR76J pVjIEHiJakVSrr9/6YNJRWw+lGHjGOYff5PwI0Ep3eKpb2V3+KrcoZoVMxFt9BPC/sWI pF2hfmg+OsDqaC33+biidaLUpk/huyRfAhGNhXWPt/SfC2f1k7Om2cF0DwYa05W3R4kv 3aJe7zwESV0rbuSL4CzqAHFpcQ035S7k3teHFD7yw4Dj7KaOYH/ZXUFuOouqcLoruTSq c/XQ== X-Gm-Message-State: AFqh2krDZxabm7T/OJ7slKs1yrOIL0jU9C0hJ1FtN4xwVo5/XqkifIz5 y7FPoyUUJZeFyschJnofujq0Xl+vMRsVsITU7FVuhQ== X-Google-Smtp-Source: AMrXdXuyDvpzUzM+vpRfHUg6lxFPMRG6IqkfA3MmEnr2bCnnRud0zzWsQ7k3n6yx9bV9RTS7q1ba5N/amCH8Svs9iIo= X-Received: by 2002:a17:902:aa4b:b0:194:b3c6:18ee with SMTP id c11-20020a170902aa4b00b00194b3c618eemr753379plr.29.1674135098305; Thu, 19 Jan 2023 05:31:38 -0800 (PST) MIME-Version: 1.0 References: <20230117220523.20911-1-eiakovlev@linux.microsoft.com> <20230117220523.20911-5-eiakovlev@linux.microsoft.com> In-Reply-To: <20230117220523.20911-5-eiakovlev@linux.microsoft.com> From: Peter Maydell Date: Thu, 19 Jan 2023 13:31:27 +0000 Message-ID: Subject: Re: [PATCH v2 4/4] hw/char/pl011: check if UART is enabled before RX or TX operation To: Evgeny Iakovlev Cc: qemu-arm@nongnu.org, qemu-devel@nongnu.org Content-Type: text/plain; charset="UTF-8" Received-SPF: pass client-ip=2607:f8b0:4864:20::102f; envelope-from=peter.maydell@linaro.org; helo=mail-pj1-x102f.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: 2.1.29 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-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Tue, 17 Jan 2023 at 22:05, Evgeny Iakovlev wrote: > > UART should be enabled in general and have RX enabled specifically to be > able to receive data from peripheral device. Same goes for transmitting > data to peripheral device and a TXE flag. > > Check if UART CR register has EN and RXE or TXE bits enabled before > trying to receive or transmit data. > > Signed-off-by: Evgeny Iakovlev > --- > hw/char/pl011.c | 22 +++++++++++++++++++--- > 1 file changed, 19 insertions(+), 3 deletions(-) Reviewed-by: Peter Maydell thanks -- PMM