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=-3.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,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 09FA1C4321D for ; Tue, 21 Aug 2018 06:26:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BFACE2175D for ; Tue, 21 Aug 2018 06:26:18 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BFACE2175D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728381AbeHUJpC (ORCPT ); Tue, 21 Aug 2018 05:45:02 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:56158 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726228AbeHUJpC (ORCPT ); Tue, 21 Aug 2018 05:45:02 -0400 Received: from localhost (5355525A.cm-6-6b.dynamic.ziggo.nl [83.85.82.90]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id CEDFAACC; Tue, 21 Aug 2018 06:26:14 +0000 (UTC) From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Mark Hounschell Subject: [PATCH 4.17 30/42] tty: serial: 8250: Revert NXP SC16C2552 workaround Date: Tue, 21 Aug 2018 08:21:02 +0200 Message-Id: <20180821055019.095020076@linuxfoundation.org> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20180821055017.596264829@linuxfoundation.org> References: <20180821055017.596264829@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.17-stable review patch. If anyone has any objections, please let me know. ------------------ From: Mark commit 47ac76662ca9c5852fd353093f19de3ae85f2e66 upstream. Revert commit ecb988a3b7985913d1f0112f66667cdd15e40711: tty: serial: 8250: 8250_core: NXP SC16C2552 workaround The above commit causes userland application to no longer write correctly its first write to a dumb terminal connected to /dev/ttyS0. This commit seems to be the culprit. It's as though the TX FIFO is being reset during that write. What should be displayed is: PSW 80000000 INST 00000000 HALT // What is displayed is some variation of: T 00000000 HAL// Reverting this commit via this patch fixes my problem. Signed-off-by: Mark Hounschell Fixes: ecb988a3b798 ("tty: serial: 8250: 8250_core: NXP SC16C2552 workaround") Cc: stable Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/8250/8250_port.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) --- a/drivers/tty/serial/8250/8250_port.c +++ b/drivers/tty/serial/8250/8250_port.c @@ -90,8 +90,7 @@ static const struct serial8250_config ua .name = "16550A", .fifo_size = 16, .tx_loadsz = 16, - .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10 | - UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT, + .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10, .rxtrig_bytes = {1, 4, 8, 14}, .flags = UART_CAP_FIFO, },