From patchwork Tue Sep 29 11:00:20 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 262894 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=-10.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 B54C4C4727F for ; Tue, 29 Sep 2020 12:42:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 632082145D for ; Tue, 29 Sep 2020 12:42:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1601383378; bh=Dd2IIfqWNOxZS/KJqjmO+3MX84wfs40Ps0T9VYm1znU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Zi1LHiUlsHlpS9qiFgJSyUfV7/lc6MNSLvtIGysSjA01N61zOK4Uu3nspHkjK43pX u6g+O1C4hfQf4ywD1zOlmncXs782rfolyyMhJ5xb7cTOn3auo0u/Dtr0T/G9huEv6c N5129GVn1SMpQSeZLBtUgsPXRa1VM5znnX1EQ0Cg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732400AbgI2Mm5 (ORCPT ); Tue, 29 Sep 2020 08:42:57 -0400 Received: from mail.kernel.org ([198.145.29.99]:50644 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729122AbgI2LKA (ORCPT ); Tue, 29 Sep 2020 07:10:00 -0400 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 916D321941; Tue, 29 Sep 2020 11:09:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1601377800; bh=Dd2IIfqWNOxZS/KJqjmO+3MX84wfs40Ps0T9VYm1znU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=zNVmMkK43tEauOVWMUok8K4dEx1bwKCtBYTw2DlQdDnGDygrTeQUFTVOS+wOzgsqt sKFxaCzuUjxTaj9XZ1U3WZCxPVLLRKt7vTqHzTNo9CLroDO7E0TS+sFW99rl3fRPk6 gH5GnSO/PYW1NU9R2EKzH8SZCGmZN7uZuMsngop8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Raviteja Narayanam , Shubhrajyoti Datta , Sasha Levin Subject: [PATCH 4.9 076/121] serial: uartps: Wait for tx_empty in console setup Date: Tue, 29 Sep 2020 13:00:20 +0200 Message-Id: <20200929105933.946548718@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200929105930.172747117@linuxfoundation.org> References: <20200929105930.172747117@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Raviteja Narayanam [ Upstream commit 42e11948ddf68b9f799cad8c0ddeab0a39da33e8 ] On some platforms, the log is corrupted while console is being registered. It is observed that when set_termios is called, there are still some bytes in the FIFO to be transmitted. So, wait for tx_empty inside cdns_uart_console_setup before calling set_termios. Signed-off-by: Raviteja Narayanam Reviewed-by: Shubhrajyoti Datta Link: https://lore.kernel.org/r/1586413563-29125-2-git-send-email-raviteja.narayanam@xilinx.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/tty/serial/xilinx_uartps.c | 8 ++++++++ 1 file changed, 8 insertions(+) --- a/drivers/tty/serial/xilinx_uartps.c +++ b/drivers/tty/serial/xilinx_uartps.c @@ -1274,6 +1274,7 @@ static int cdns_uart_console_setup(struc int bits = 8; int parity = 'n'; int flow = 'n'; + unsigned long time_out; if (co->index < 0 || co->index >= CDNS_UART_NR_PORTS) return -EINVAL; @@ -1287,6 +1288,13 @@ static int cdns_uart_console_setup(struc if (options) uart_parse_options(options, &baud, &parity, &bits, &flow); + /* Wait for tx_empty before setting up the console */ + time_out = jiffies + usecs_to_jiffies(TX_TIMEOUT); + + while (time_before(jiffies, time_out) && + cdns_uart_tx_empty(port) != TIOCSER_TEMT) + cpu_relax(); + return uart_set_options(port, co, baud, parity, bits, flow); }