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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,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 B9A33C432C0 for ; Fri, 22 Nov 2019 06:06:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 844AA2068E for ; Fri, 22 Nov 2019 06:06:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574402817; bh=d0ntVbZyiTVQFUBkfKqRFVdd7wKYeRXw4kRDxXAxktk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=MTZ36NUXeaclB0cSEexsta+CM47PDt9CcKcdVgnXMkIliLK0vAmrFJvS7jeYiRhsf t9b0m1zNl+nFxqK2jy75OXBdY/cRTYBR0TEX7Yf3+r9c9s9RpFwJbtAYWo1mZZRib3 c6myGFEYYJ9385D8UZMz+IRU4OJdJ5XA+e6SUUuM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729468AbfKVGG4 (ORCPT ); Fri, 22 Nov 2019 01:06:56 -0500 Received: from mail.kernel.org ([198.145.29.99]:40730 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729639AbfKVGCN (ORCPT ); Fri, 22 Nov 2019 01:02:13 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 0087F20715; Fri, 22 Nov 2019 06:02:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574402532; bh=d0ntVbZyiTVQFUBkfKqRFVdd7wKYeRXw4kRDxXAxktk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=iABZwBkib8v1bRpr+uPWNhit+pknhoR5F+BxAiHFnMk0diSINCTu7JizEuVGqCVjA zQdPhetjP0i5aWm1pD9wPlb0Kh8uHZixyBHt30LonKphGPcdp6AIVZJAsBzVGklNYS uD9j4Hr9zm1jB1srMBVXTATDPhnx2ZEnIILmUuWM= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Alexander Shiyan , Greg Kroah-Hartman , Sasha Levin , linux-serial@vger.kernel.org Subject: [PATCH AUTOSEL 4.9 40/91] serial: max310x: Fix tx_empty() callback Date: Fri, 22 Nov 2019 01:00:38 -0500 Message-Id: <20191122060129.4239-39-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191122060129.4239-1-sashal@kernel.org> References: <20191122060129.4239-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Alexander Shiyan [ Upstream commit a8da3c7873ea57acb8f9cea58c0af477522965aa ] Function max310x_tx_empty() accesses the IRQSTS register, which is cleared by IC when reading, so if there is an interrupt status, we will lose it. This patch implement the transmitter check only by the current FIFO level. Signed-off-by: Alexander Shiyan Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/tty/serial/max310x.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) diff --git a/drivers/tty/serial/max310x.c b/drivers/tty/serial/max310x.c index bacc7e284c0c1..80ab672d61cc4 100644 --- a/drivers/tty/serial/max310x.c +++ b/drivers/tty/serial/max310x.c @@ -769,12 +769,9 @@ static void max310x_start_tx(struct uart_port *port) static unsigned int max310x_tx_empty(struct uart_port *port) { - unsigned int lvl, sts; + u8 lvl = max310x_port_read(port, MAX310X_TXFIFOLVL_REG); - lvl = max310x_port_read(port, MAX310X_TXFIFOLVL_REG); - sts = max310x_port_read(port, MAX310X_IRQSTS_REG); - - return ((sts & MAX310X_IRQ_TXEMPTY_BIT) && !lvl) ? TIOCSER_TEMT : 0; + return lvl ? 0 : TIOCSER_TEMT; } static unsigned int max310x_get_mctrl(struct uart_port *port) -- 2.20.1