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=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 D6FCCC11F69 for ; Fri, 2 Jul 2021 13:43:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C65F9613CE for ; Fri, 2 Jul 2021 13:43:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232785AbhGBNpf (ORCPT ); Fri, 2 Jul 2021 09:45:35 -0400 Received: from mail.kernel.org ([198.145.29.99]:48832 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232715AbhGBNp2 (ORCPT ); Fri, 2 Jul 2021 09:45:28 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 9568D61440; Fri, 2 Jul 2021 13:42:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1625233376; bh=O2JgpgSzI1fK5NYzIru4yBvKZ6mUJEW0O262pd1WwYE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cTIiCwCyL3ELZzd2S5qLC9HwdtSqgU5rQfAHOPoYG0Jdn6Cr8/i5pFePOemmbjt5n eoYha9t5Zk19wzMyxH81oLlLDjyKQNe4TW6wYPyD4j/fl5r3jjYGvG0k8rhiZ3Csiw ExP8LHakS3Q6IRqHxDSzDnlBNtFQjzKnkK583LipZ95vEjlUc04yKR/qXk96h88P4a omPz8i9cgo30+BjT6Lj0gTRbcHpjtWODg6Db/bESkAHcL5GREfQ9NtIM75bs25Wfzm WaX8wlsWVdsSC9T1jSCZquPYOjNgU+nkLQiTFxsD/aJnTO4fDk/TqCaoNiDEzPJc2Y Z+J6IU5RRJQhg== Received: from johan by xi.lan with local (Exim 4.94.2) (envelope-from ) id 1lzJRT-0006Q4-2s; Fri, 02 Jul 2021 15:42:51 +0200 From: Johan Hovold To: Johan Hovold Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: [PATCH 2/6] USB: serial: cp210x: fix flow-control error handling Date: Fri, 2 Jul 2021 15:42:23 +0200 Message-Id: <20210702134227.24621-3-johan@kernel.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210702134227.24621-1-johan@kernel.org> References: <20210702134227.24621-1-johan@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Make sure that the driver crtscts state is not updated in the unlikely event that the flow-control request fails. Not doing so could break RTS control. Fixes: 5951b8508855 ("USB: serial: cp210x: suppress modem-control errors") Cc: stable@vger.kernel.org # 5.11 Signed-off-by: Johan Hovold --- drivers/usb/serial/cp210x.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/drivers/usb/serial/cp210x.c b/drivers/usb/serial/cp210x.c index b41e2c7649fb..eb3be4f65603 100644 --- a/drivers/usb/serial/cp210x.c +++ b/drivers/usb/serial/cp210x.c @@ -1191,6 +1191,7 @@ static void cp210x_set_flow_control(struct tty_struct *tty, struct cp210x_flow_ctl flow_ctl; u32 flow_repl; u32 ctl_hs; + bool crtscts; int ret; /* @@ -1246,14 +1247,14 @@ static void cp210x_set_flow_control(struct tty_struct *tty, flow_repl |= CP210X_SERIAL_RTS_FLOW_CTL; else flow_repl |= CP210X_SERIAL_RTS_INACTIVE; - port_priv->crtscts = true; + crtscts = true; } else { ctl_hs &= ~CP210X_SERIAL_CTS_HANDSHAKE; if (port_priv->rts) flow_repl |= CP210X_SERIAL_RTS_ACTIVE; else flow_repl |= CP210X_SERIAL_RTS_INACTIVE; - port_priv->crtscts = false; + crtscts = false; } if (I_IXOFF(tty)) { @@ -1276,8 +1277,12 @@ static void cp210x_set_flow_control(struct tty_struct *tty, flow_ctl.ulControlHandshake = cpu_to_le32(ctl_hs); flow_ctl.ulFlowReplace = cpu_to_le32(flow_repl); - cp210x_write_reg_block(port, CP210X_SET_FLOW, &flow_ctl, + ret = cp210x_write_reg_block(port, CP210X_SET_FLOW, &flow_ctl, sizeof(flow_ctl)); + if (ret) + goto out_unlock; + + port_priv->crtscts = crtscts; out_unlock: mutex_unlock(&port_priv->mutex); } -- 2.31.1