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=-19.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 18822C432C3 for ; Wed, 23 Dec 2020 02:57:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D3BAE206F6 for ; Wed, 23 Dec 2020 02:57:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727554AbgLWC5a (ORCPT ); Tue, 22 Dec 2020 21:57:30 -0500 Received: from mail.kernel.org ([198.145.29.99]:49514 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729063AbgLWCUn (ORCPT ); Tue, 22 Dec 2020 21:20:43 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 1D06D22202; Wed, 23 Dec 2020 02:20:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1608690002; bh=O4qMQroSwZ+/X2Ecyn7WFV296lPaetdg1kz/ioPO50Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jPLBh5bVa1rW67lWELGYteOWxbtO7CfANo7XsjxBJSMIQrWiGELFPi1dQvuzuI84s sso/PXmqgy7YDiN5O8NL6/NEsFHned2pvwjEFHSLGI+ZXLCxrj9B5CfIQvIC4jebj/ 9R79ydcnF9wUk2w5xrRSIhXie1alIV9eh6TGOs/hPgfKMaE7gR3OA4j1FimVVCSGlt ZFToUahRrr1Wh5phaP7WnpDXaaLdHOFoiMSJ5eT2yx1Hwes1MuRSVPnFZA8bI8pA4z r6arHjgdY0G9m9XfZbqxsJ1l+8avUoCrY9dfqcjxfEiTrw6ZtJvtpcQmQLhLGDMX91 w/2fO9wBCMsEQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Mingrui Ren , Greg Kroah-Hartman , Sasha Levin , linux-serial@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH AUTOSEL 5.4 084/130] tty/serial/imx: Enable TXEN bit in imx_poll_init(). Date: Tue, 22 Dec 2020 21:17:27 -0500 Message-Id: <20201223021813.2791612-84-sashal@kernel.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20201223021813.2791612-1-sashal@kernel.org> References: <20201223021813.2791612-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Mingrui Ren [ Upstream commit aef1b6a27970607721a618a0b990716ca8dbbf97 ] As described in Documentation, poll_init() is called by kgdb to initialize hardware which supports both poll_put_char() and poll_get_char(). It's necessary to enable TXEN bit, otherwise, it will cause hardware fault and kernel panic when calling imx_poll_put_char(). Generally, if use /dev/ttymxc0 as kgdb console as well as system console, ttymxc0 is initialized early by system console which does enable TXEN bit.But when use /dev/ttymxc1 as kgbd console, ttymxc1 is only initialized by imx_poll_init() cannot enable the TXEN bit, which will cause kernel panic. Signed-off-by: Mingrui Ren Link: https://lore.kernel.org/r/20201202072543.151-1-972931182@qq.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/tty/serial/imx.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c index e5ed4ab2b08df..982953db58e95 100644 --- a/drivers/tty/serial/imx.c +++ b/drivers/tty/serial/imx.c @@ -1811,7 +1811,7 @@ static int imx_uart_poll_init(struct uart_port *port) ucr1 |= UCR1_UARTEN; ucr1 &= ~(UCR1_TRDYEN | UCR1_RTSDEN | UCR1_RRDYEN); - ucr2 |= UCR2_RXEN; + ucr2 |= UCR2_RXEN | UCR2_TXEN; ucr2 &= ~UCR2_ATEN; imx_uart_writel(sport, ucr1, UCR1); -- 2.27.0