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=-6.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,T_DKIMWL_WL_HIGH,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 38DBEC2BCA1 for ; Fri, 7 Jun 2019 15:42:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0F97A21530 for ; Fri, 7 Jun 2019 15:42:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1559922157; bh=Jf33kmLLFmEOiNWvM0nQgXO0kil+1qKY4cJex/Oqgak=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=gQmnl8V8U76Bcz8blfY2wucfIMWLjpo+HowgojCNWTMVTZXGZYrQAt0V6p0VJODGR 4BiGu6rLNyCjUvJqFCMwToNJhg5i0XfTxuMrud7Mzj0K4bMr0dqvL4khkuM2aj4fT1 uRvgpDa5iEOSaaA/k3nPc70FOo0vaDlSR4Xm8sWo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728873AbfFGPmg (ORCPT ); Fri, 7 Jun 2019 11:42:36 -0400 Received: from mail.kernel.org ([198.145.29.99]:53278 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730604AbfFGPmd (ORCPT ); Fri, 7 Jun 2019 11:42:33 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 89132214C6; Fri, 7 Jun 2019 15:42:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1559922153; bh=Jf33kmLLFmEOiNWvM0nQgXO0kil+1qKY4cJex/Oqgak=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pr1dL4kri3GG4GAjxJHXoADY+SYs7TOMT0salUBXqtThkWAXPChF+CE5YzkbvkPQ2 clxFc1fHu7Fo+itRE2H0r8Tggity5k7Wh4CBI6XV4fesQxHdQ07P0kY7C2ClGa9cEw bvZ5Z4E7ptrgIFI2bqULRr/Kgc+OQnrWGAjt59+g= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Michael Rodin , Eugeniu Rosca , Simon Horman , Wolfram Sang , Geert Uytterhoeven , "George G. Davis" Subject: [PATCH 4.14 56/69] serial: sh-sci: disable DMA for uart_console Date: Fri, 7 Jun 2019 17:39:37 +0200 Message-Id: <20190607153855.055695580@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190607153848.271562617@linuxfoundation.org> References: <20190607153848.271562617@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: George G. Davis commit 099506cbbc79c0bd52b19cb6b930f256dabc3950 upstream. As noted in commit 84b40e3b57ee ("serial: 8250: omap: Disable DMA for console UART"), UART console lines use low-level PIO only access functions which will conflict with use of the line when DMA is enabled, e.g. when the console line is also used for systemd messages. So disable DMA support for UART console lines. Reported-by: Michael Rodin Link: https://patchwork.kernel.org/patch/10929511/ Tested-by: Eugeniu Rosca Reviewed-by: Simon Horman Reviewed-by: Wolfram Sang Reviewed-by: Geert Uytterhoeven Cc: stable@vger.kernel.org Signed-off-by: George G. Davis Signed-off-by: Greg Kroah-Hartman Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/sh-sci.c | 7 +++++++ 1 file changed, 7 insertions(+) --- a/drivers/tty/serial/sh-sci.c +++ b/drivers/tty/serial/sh-sci.c @@ -1479,6 +1479,13 @@ static void sci_request_dma(struct uart_ dev_dbg(port->dev, "%s: port %d\n", __func__, port->line); + /* + * DMA on console may interfere with Kernel log messages which use + * plain putchar(). So, simply don't use it with a console. + */ + if (uart_console(port)) + return; + if (!port->dev->of_node) return;