From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1423014AbcE3Vpk (ORCPT ); Mon, 30 May 2016 17:45:40 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:52973 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1422725AbcE3VAi (ORCPT ); Mon, 30 May 2016 17:00:38 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Chanwoo Choi , Marek Szyprowski , Krzysztof Kozlowski Subject: [PATCH 4.5 70/87] serial: samsung: Reorder the sequence of clock control when call s3c24xx_serial_set_termios() Date: Mon, 30 May 2016 13:50:08 -0700 Message-Id: <20160530204936.116211872@linuxfoundation.org> X-Mailer: git-send-email 2.8.3 In-Reply-To: <20160530204933.149873142@linuxfoundation.org> References: <20160530204933.149873142@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.5-stable review patch. If anyone has any objections, please let me know. ------------------ From: Chanwoo Choi commit b8995f527aac143e83d3900ff39357651ea4e0f6 upstream. This patch fixes the broken serial log when changing the clock source of uart device. Before disabling the original clock source, this patch enables the new clock source to protect the clock off state for a split second. Signed-off-by: Chanwoo Choi Reviewed-by: Marek Szyprowski Signed-off-by: Greg Kroah-Hartman Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Krzysztof Kozlowski --- drivers/tty/serial/samsung.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/drivers/tty/serial/samsung.c +++ b/drivers/tty/serial/samsung.c @@ -1263,6 +1263,8 @@ static void s3c24xx_serial_set_termios(s /* check to see if we need to change clock source */ if (ourport->baudclk != clk) { + clk_prepare_enable(clk); + s3c24xx_serial_setsource(port, clk_sel); if (!IS_ERR(ourport->baudclk)) { @@ -1270,8 +1272,6 @@ static void s3c24xx_serial_set_termios(s ourport->baudclk = ERR_PTR(-EINVAL); } - clk_prepare_enable(clk); - ourport->baudclk = clk; ourport->baudclk_rate = clk ? clk_get_rate(clk) : 0; }