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=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,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 33B69C433DF for ; Mon, 17 Aug 2020 17:35:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0448A20716 for ; Mon, 17 Aug 2020 17:35:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597685723; bh=oH4VHohmkYgfHQ4bhyNLNm4/Q8IS8mB1/jcuedtF8ps=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=YFFDpNfeGwVU6qFwZzhJHZqct5pM3geESJ4UDfMZN10sGKAh1unrRfKnS6tImRi8Z uqM4REBcfpDIyTaNUTsl5+1wyttL3Ef2EzaKndMLGxTzpbWAnH3WXcdXFb7/VGanGH 9c9Tvkni8+VBTGUrEj2gS4zzUYpn/WQDab0cdt3U= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730032AbgHQRfU (ORCPT ); Mon, 17 Aug 2020 13:35:20 -0400 Received: from mail.kernel.org ([198.145.29.99]:56220 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730322AbgHQQRu (ORCPT ); Mon, 17 Aug 2020 12:17:50 -0400 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 E567822CAF; Mon, 17 Aug 2020 16:17:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597681068; bh=oH4VHohmkYgfHQ4bhyNLNm4/Q8IS8mB1/jcuedtF8ps=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=VX6Ub9N/TM6uIQk7G4JaZWsPREO85LAqGlx/8JWlHdNeqaVM2xvnsbMptz/8641ua twPx7zRoODczuNi4WmPhxNeZYTjRX2ClM6y0krzC2OujwQTKTA22HL2QJYde9vvAFH lmBSoi6mANQ4hN3BzlZZ3F80AQtTDQSX6yCyOCbI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Brant Merryman , Phu Luu , Johan Hovold Subject: [PATCH 4.19 138/168] USB: serial: cp210x: re-enable auto-RTS on open Date: Mon, 17 Aug 2020 17:17:49 +0200 Message-Id: <20200817143740.592062851@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200817143733.692105228@linuxfoundation.org> References: <20200817143733.692105228@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: Brant Merryman commit c7614ff9b73a1e6fb2b1b51396da132ed22fecdb upstream. CP210x hardware disables auto-RTS but leaves auto-CTS when in hardware flow control mode and UART on cp210x hardware is disabled. When re-opening the port, if auto-CTS is enabled on the cp210x, then auto-RTS must be re-enabled in the driver. Signed-off-by: Brant Merryman Co-developed-by: Phu Luu Signed-off-by: Phu Luu Link: https://lore.kernel.org/r/ECCF8E73-91F3-4080-BE17-1714BC8818FB@silabs.com [ johan: fix up tags and problem description ] Fixes: 39a66b8d22a3 ("[PATCH] USB: CP2101 Add support for flow control") Cc: stable # 2.6.12 Signed-off-by: Johan Hovold Signed-off-by: Greg Kroah-Hartman --- drivers/usb/serial/cp210x.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) --- a/drivers/usb/serial/cp210x.c +++ b/drivers/usb/serial/cp210x.c @@ -893,6 +893,7 @@ static void cp210x_get_termios_port(stru u32 baud; u16 bits; u32 ctl_hs; + u32 flow_repl; cp210x_read_u32_reg(port, CP210X_GET_BAUDRATE, &baud); @@ -993,6 +994,22 @@ static void cp210x_get_termios_port(stru ctl_hs = le32_to_cpu(flow_ctl.ulControlHandshake); if (ctl_hs & CP210X_SERIAL_CTS_HANDSHAKE) { dev_dbg(dev, "%s - flow control = CRTSCTS\n", __func__); + /* + * When the port is closed, the CP210x hardware disables + * auto-RTS and RTS is deasserted but it leaves auto-CTS when + * in hardware flow control mode. When re-opening the port, if + * auto-CTS is enabled on the cp210x, then auto-RTS must be + * re-enabled in the driver. + */ + flow_repl = le32_to_cpu(flow_ctl.ulFlowReplace); + flow_repl &= ~CP210X_SERIAL_RTS_MASK; + flow_repl |= CP210X_SERIAL_RTS_SHIFT(CP210X_SERIAL_RTS_FLOW_CTL); + flow_ctl.ulFlowReplace = cpu_to_le32(flow_repl); + cp210x_write_reg_block(port, + CP210X_SET_FLOW, + &flow_ctl, + sizeof(flow_ctl)); + cflag |= CRTSCTS; } else { dev_dbg(dev, "%s - flow control = NONE\n", __func__);