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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 EF8CFC43603 for ; Wed, 4 Dec 2019 17:59:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BC7F52073B for ; Wed, 4 Dec 2019 17:59:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1575482346; bh=jzremZJt9uCCXqYmgSJYucLdl1Qtl9dFmP4sQefk5tQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=pTgku/3oxE4QKBEd6aGtC5aIi8vyWDPfa4y+zH+VswMsSDHWvjUrzHgvuXjl8X63M cfmk6hFFVtXAXXKFjodsPsQp5HeVwc6Wu7tHfY9bGw8qyVV3LyNPMj2CK92hNg6ZuE 8XC+jkfDZ+xZ1+gD0rjpo4JL6QqWNnA8aN882SeA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729025AbfLDR7G (ORCPT ); Wed, 4 Dec 2019 12:59:06 -0500 Received: from mail.kernel.org ([198.145.29.99]:34702 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729008AbfLDR7B (ORCPT ); Wed, 4 Dec 2019 12:59:01 -0500 Received: from localhost (unknown [217.68.49.72]) (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 AAD092073B; Wed, 4 Dec 2019 17:59:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1575482341; bh=jzremZJt9uCCXqYmgSJYucLdl1Qtl9dFmP4sQefk5tQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=YqO8vHEYdvJ8TmGXkoiktfXAKv6UvNknJjRZg82CvYyQf/jyx0KSRFtNNmTc9GRFr FLa5zAo0lk7E1MWxdjgyG62L2xamtWd4pE+nad7aPaa1ktQgkgISwnXaa2z87UKXeC exQlOb3JthV8Gf81ZZWd4kjXfTaWXXpIPN1P+afU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Alexander Shiyan , Sasha Levin Subject: [PATCH 4.4 41/92] serial: max310x: Fix tx_empty() callback Date: Wed, 4 Dec 2019 18:49:41 +0100 Message-Id: <20191204174333.005303985@linuxfoundation.org> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191204174327.215426506@linuxfoundation.org> References: <20191204174327.215426506@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: 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 a66fb7afecc71..e13e95733fa3c 100644 --- a/drivers/tty/serial/max310x.c +++ b/drivers/tty/serial/max310x.c @@ -763,12 +763,9 @@ 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