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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 BA772C3B18B for ; Thu, 13 Feb 2020 15:40:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 88A90217F4 for ; Thu, 13 Feb 2020 15:40:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581608421; bh=LkzOpvLNFl2lEwT/T4BDYoR8AVuZdWX6UF//DtE/FSU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=TRWhHJi8xohCmZrt5wnQs4MKcKxA1mL3ImFf48+7cgXlhhNcOyxWH8q6jQb9S0EiT cA38/9tEYIxqB+4bUzvdVjjbPLZMhvwx21MuBKnyxF8sRyVQTw+sN2Es2YFHHsh/Pr 9PUvBVxXMy4vA1JdyBOvokf7TCsPSnSiTz6YYnDM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387693AbgBMP2p (ORCPT ); Thu, 13 Feb 2020 10:28:45 -0500 Received: from mail.kernel.org ([198.145.29.99]:44220 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729192AbgBMP0O (ORCPT ); Thu, 13 Feb 2020 10:26:14 -0500 Received: from localhost (unknown [104.132.1.104]) (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 6F9CC20848; Thu, 13 Feb 2020 15:26:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581607573; bh=LkzOpvLNFl2lEwT/T4BDYoR8AVuZdWX6UF//DtE/FSU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=fal4O9kGRV3d5bibcBmI7oHM6rUkSHOWsxBZKHfTlOB1DfLYLpYTdCRMY6+K7JMia JBTAO+x4JRUBbeGOvxGbQOECcVYZVLYufn4ysAbYYqfQehhQx7FtArcFuj9k3VTzbH FwEKbG0C4F9xqmxYYFqeQ3yWWZT55K6iJF9w+bzI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jean-Francois Dagenais , Shubhrajyoti Datta , Sasha Levin Subject: [PATCH 4.14 150/173] serial: uartps: Add a timeout to the tx empty wait Date: Thu, 13 Feb 2020 07:20:53 -0800 Message-Id: <20200213152009.387256080@linuxfoundation.org> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200213151931.677980430@linuxfoundation.org> References: <20200213151931.677980430@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: Shubhrajyoti Datta [ Upstream commit 277375b864e8147975b064b513f491e2a910e66a ] In case the cable is not connected then the target gets into an infinite wait for tx empty. Add a timeout to the tx empty wait. Reported-by: Jean-Francois Dagenais Signed-off-by: Shubhrajyoti Datta Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/tty/serial/xilinx_uartps.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) --- a/drivers/tty/serial/xilinx_uartps.c +++ b/drivers/tty/serial/xilinx_uartps.c @@ -31,6 +31,7 @@ #include #include #include +#include #define CDNS_UART_TTY_NAME "ttyPS" #define CDNS_UART_NAME "xuartps" @@ -39,6 +40,7 @@ #define CDNS_UART_NR_PORTS 2 #define CDNS_UART_FIFO_SIZE 64 /* FIFO size */ #define CDNS_UART_REGISTER_SPACE 0x1000 +#define TX_TIMEOUT 500000 /* Rx Trigger level */ static int rx_trigger_level = 56; @@ -685,16 +687,20 @@ static void cdns_uart_set_termios(struct unsigned int cval = 0; unsigned int baud, minbaud, maxbaud; unsigned long flags; - unsigned int ctrl_reg, mode_reg; + unsigned int ctrl_reg, mode_reg, val; + int err; spin_lock_irqsave(&port->lock, flags); /* Wait for the transmit FIFO to empty before making changes */ if (!(readl(port->membase + CDNS_UART_CR) & CDNS_UART_CR_TX_DIS)) { - while (!(readl(port->membase + CDNS_UART_SR) & - CDNS_UART_SR_TXEMPTY)) { - cpu_relax(); + err = readl_poll_timeout(port->membase + CDNS_UART_SR, + val, (val & CDNS_UART_SR_TXEMPTY), + 1000, TX_TIMEOUT); + if (err) { + dev_err(port->dev, "timed out waiting for tx empty"); + return; } }