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=-10.5 required=3.0 tests=BAYES_00,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 771FBC4727F for ; Tue, 29 Sep 2020 11:11:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 39C79221E7 for ; Tue, 29 Sep 2020 11:11:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1601377863; bh=HxKxLArqv0zTXU/qx0NU1qQYE/H9Vb0E6/1RbvoyXo4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=1Tk6t60zXWESvhMyJAID9EomjdOAQhhIFLWib6YrcU+jvYPP9NNE57v/5e0JZxI5O hHx8RrfRabRky3uFWLOlZPrGHZUqaTNvpX3ZMpsE4EsOzeHp7uLIDkY26uGCboah3U JYWa0sfozE6Ss0ygcV7h0A+PFAOddirSDFpUxoZc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729130AbgI2LKG (ORCPT ); Tue, 29 Sep 2020 07:10:06 -0400 Received: from mail.kernel.org ([198.145.29.99]:50548 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728681AbgI2LJ6 (ORCPT ); Tue, 29 Sep 2020 07:09:58 -0400 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (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 CA55121D7F; Tue, 29 Sep 2020 11:09:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1601377797; bh=HxKxLArqv0zTXU/qx0NU1qQYE/H9Vb0E6/1RbvoyXo4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=eHQL/P33+4CpusKumvsfrmzwGwQ1KFreK90RWdDqWMMrxsiBo3WcmvkqxO9yoFlhC yX3jgvSjpleSqzL7NnvY9A+IeubO+s9NmaLm2V9OSDlbNd185DzRoQIT1pI6VsJG6i VVH/7kgbrilUoihAbIOrEOEPQHmm4l+qaUa66TtA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jean-Francois Dagenais , Shubhrajyoti Datta Subject: [PATCH 4.9 075/121] serial: uartps: Add a timeout to the tx empty wait Date: Tue, 29 Sep 2020 13:00:19 +0200 Message-Id: <20200929105933.897487544@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200929105930.172747117@linuxfoundation.org> References: <20200929105930.172747117@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Shubhrajyoti Datta commit 277375b864e8147975b064b513f491e2a910e66a upstream. 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: Greg Kroah-Hartman --- 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 @@ -30,6 +30,7 @@ #include #include #include +#include #define CDNS_UART_TTY_NAME "ttyPS" #define CDNS_UART_NAME "xuartps" @@ -38,6 +39,7 @@ #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; @@ -681,16 +683,20 @@ 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; } }