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,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 29F0FC432C0 for ; Tue, 19 Nov 2019 05:51:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 019BA208C3 for ; Tue, 19 Nov 2019 05:51:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574142713; bh=2Ryiu54J7RjdKSMXF03LaKQ2DIslLnR9lwAhh7kigR0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=OWDTMu23be2SsB8RZ2hjIDVRNA13WY4twnXgMXt8O6IVnMUcpuMeVoR0BGBC9ekE1 4sQ0ijD5acsYYmBzLytr+Anrz+8yyRJM25UE7jGCwicRqY6iEYlsVl/BRGGHB6ZpRl keZmpMl8+NIOX61INy6qxP4XcUrk3J79dbBQzgZo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731514AbfKSFvv (ORCPT ); Tue, 19 Nov 2019 00:51:51 -0500 Received: from mail.kernel.org ([198.145.29.99]:49350 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731843AbfKSFvt (ORCPT ); Tue, 19 Nov 2019 00:51:49 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 38EE6208C3; Tue, 19 Nov 2019 05:51:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574142708; bh=2Ryiu54J7RjdKSMXF03LaKQ2DIslLnR9lwAhh7kigR0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=en3qPCVROYEmx0OoprYHXcbE0j+rSXkJfGg5wdHo5S9M/ixWJxl64MTYKvMs0alB5 ZXOiQ0MK8+GGrqgF2UeAJKjUeRDN+XS/vBfIhbjonBk+XvHia/KzXjc1wjrRSlzBie hbG5husIqJS6olvXgKhGyEgdDFac8k7CBepRY6WA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Nava kishore Manne , Michal Simek , Sasha Levin Subject: [PATCH 4.14 132/239] serial: uartps: Fix suspend functionality Date: Tue, 19 Nov 2019 06:18:52 +0100 Message-Id: <20191119051330.773039084@linuxfoundation.org> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191119051255.850204959@linuxfoundation.org> References: <20191119051255.850204959@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: Nava kishore Manne [ Upstream commit 4b9d33c6a30688344a3e95179654ea31b07f59b7 ] The driver's suspend/resume functions were buggy. If UART node contains any child node in the DT and the child is established a communication path with the parent UART. The relevant /dev/ttyPS* node will be not available for other operations. If the driver is trying to do any operations like suspend/resume without checking the tty->dev status it leads to the kernel crash/hang. This patch fix this issue by call the device_may_wake() with the generic parameter of type struct device. in the uart suspend and resume paths. It also fixes a race condition in the uart suspend path(i.e uart_suspend_port() should be called at the end of cdns_uart_suspend API this path updates the same) Signed-off-by: Nava kishore Manne Signed-off-by: Michal Simek Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/tty/serial/xilinx_uartps.c | 41 +++++++++--------------------- 1 file changed, 12 insertions(+), 29 deletions(-) diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c index b0da63737aa19..0dbfd02e3b196 100644 --- a/drivers/tty/serial/xilinx_uartps.c +++ b/drivers/tty/serial/xilinx_uartps.c @@ -1342,24 +1342,11 @@ static struct uart_driver cdns_uart_uart_driver = { static int cdns_uart_suspend(struct device *device) { struct uart_port *port = dev_get_drvdata(device); - struct tty_struct *tty; - struct device *tty_dev; - int may_wake = 0; - - /* Get the tty which could be NULL so don't assume it's valid */ - tty = tty_port_tty_get(&port->state->port); - if (tty) { - tty_dev = tty->dev; - may_wake = device_may_wakeup(tty_dev); - tty_kref_put(tty); - } + int may_wake; - /* - * Call the API provided in serial_core.c file which handles - * the suspend. - */ - uart_suspend_port(&cdns_uart_uart_driver, port); - if (!(console_suspend_enabled && !may_wake)) { + may_wake = device_may_wakeup(device); + + if (console_suspend_enabled && may_wake) { unsigned long flags = 0; spin_lock_irqsave(&port->lock, flags); @@ -1374,7 +1361,11 @@ static int cdns_uart_suspend(struct device *device) spin_unlock_irqrestore(&port->lock, flags); } - return 0; + /* + * Call the API provided in serial_core.c file which handles + * the suspend. + */ + return uart_suspend_port(&cdns_uart_uart_driver, port); } /** @@ -1388,17 +1379,9 @@ static int cdns_uart_resume(struct device *device) struct uart_port *port = dev_get_drvdata(device); unsigned long flags = 0; u32 ctrl_reg; - struct tty_struct *tty; - struct device *tty_dev; - int may_wake = 0; - - /* Get the tty which could be NULL so don't assume it's valid */ - tty = tty_port_tty_get(&port->state->port); - if (tty) { - tty_dev = tty->dev; - may_wake = device_may_wakeup(tty_dev); - tty_kref_put(tty); - } + int may_wake; + + may_wake = device_may_wakeup(device); if (console_suspend_enabled && !may_wake) { struct cdns_uart *cdns_uart = port->private_data; -- 2.20.1