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=-6.7 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham 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 5A5FBC5AE5E for ; Sat, 19 Jan 2019 00:31:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2528320823 for ; Sat, 19 Jan 2019 00:31:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="oA3VNzX3" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730264AbfASAbN (ORCPT ); Fri, 18 Jan 2019 19:31:13 -0500 Received: from mail-pf1-f195.google.com ([209.85.210.195]:41605 "EHLO mail-pf1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730159AbfASAbM (ORCPT ); Fri, 18 Jan 2019 19:31:12 -0500 Received: by mail-pf1-f195.google.com with SMTP id b7so7362711pfi.8 for ; Fri, 18 Jan 2019 16:31:11 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=Sd+gwOo5E4dkuf4Q6i8JvdMw7Stn3ZJ/xuY+z66pxp8=; b=oA3VNzX3bnQsIF+UkffAZ2wgMaE+zvZWqNg94TTjaV6spVo1EZmId5LhAR9U3kg3Rf bo87YaFm4ExZiqEeI8JNFjoH0xhhIpIiq9zqOhFk8XadY45FUxnibwkrSqtkZkNBK8Lr kYUaocAI89Ep6MQo0Yv1crVQFF94Mth6jL/sI= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=Sd+gwOo5E4dkuf4Q6i8JvdMw7Stn3ZJ/xuY+z66pxp8=; b=gaucsRz/ocl610syLtc7SFhfC+Dmamyt82V5jeoBhmFJV+mJrsb9kbNa8C6jG8akcm HKCi0Ga1V/GXjPGtBMTdpD8dA/B++n5S3Zi7K+wbrvH/JljspY2CZdpqxt4YpzQhoKKh r7JnuRwl9InO68chx3hTABjLHE1C7ztngZYTU9WcVit6YSdaWsTlwRDoe5OKtX9EpPOz SxVJqT30QEmXWdGC14Xln30cBS1XjrAf7cn0ogCOMggknj0TWsrUauGXKYfY47Hs7wwC wZ1LfCiCacm7vUk5XjGSa/z21Ar84vqBZIT3+ETXIblHR3lhTuOibLTrW0tz/5TmPWAM mGFA== X-Gm-Message-State: AJcUukeQs0SYOPVFpGrd2I+CU1RgaC89UT9+E3NjuLKuKXd46igg6zPh 6CQyZTss6gn7rOTJtoUi0tfT7A== X-Google-Smtp-Source: ALg8bN5oODdLlAZyklgwdzaHEQrU0y01J2dK24MCqQvbNSaRWzmMpr17C9P/2k541Da/gT6P/ZXpqw== X-Received: by 2002:a63:c051:: with SMTP id z17mr19393530pgi.20.1547857871519; Fri, 18 Jan 2019 16:31:11 -0800 (PST) Received: from localhost ([2620:15c:202:1:75a:3f6e:21d:9374]) by smtp.gmail.com with ESMTPSA id q195sm6681095pgq.7.2019.01.18.16.31.10 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Fri, 18 Jan 2019 16:31:10 -0800 (PST) Date: Fri, 18 Jan 2019 16:31:09 -0800 From: Matthias Kaehlcke To: Johan Hovold Cc: Balakrishna Godavarthi , marcel@holtmann.org, johan.hedberg@gmail.com, linux-kernel@vger.kernel.org, linux-bluetooth@vger.kernel.org, hemantg@codeaurora.org, linux-arm-msm@vger.kernel.org, Johan Hovold Subject: Re: [PATCH v5 2/5] Bluetooth: hci_qca: Deassert RTS while baudrate change command Message-ID: <20190119003109.GD261387@google.com> References: <20190110143928.GE3430@localhost> <61301df80bd6a8ee0265b31b7f6a3aa1@codeaurora.org> <20190111013707.GD261387@google.com> <194b5d18ea86830b6a24939d483a964c@codeaurora.org> <20190111235633.GK261387@google.com> <20190115234628.GQ261387@google.com> <20190117160944.GV3691@localhost> <20190117172109.GU261387@google.com> <20190118094416.GB3691@localhost> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20190118094416.GB3691@localhost> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jan 18, 2019 at 10:44:16AM +0100, Johan Hovold wrote: > On Thu, Jan 17, 2019 at 09:21:09AM -0800, Matthias Kaehlcke wrote: > > > I observed that the qcom_geni_serial driver doesn't raise RTS with > > flow control disabled. It seems we have to investigate why that's the > > case. I agree that the driver should be platform agnostic. > > Sounds like a driver bug, unless the hardware is just "odd". The > driver implementation of this looks very non-standard judging from a > quick peek. > > In fact, qcom_geni_serial_get_mctrl() is currently a no-op if hardware > flow control is not enabled: > > if (uart_console(uport) || !uart_cts_enabled(uport)) > return; > > Perhaps dropping the !uart_cts_enabled() test is sufficient. Thanks for taking a look Johan, that was indeed the problem (also in set_mctrl()). I posted a fix: https://lore.kernel.org/patchwork/patch/1033611/ Balakrishna, the following (applied on top of your patch) works for me with the UART patch above: diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c index 9d5e41f159c78f..60bfdf01f72841 100644 --- a/drivers/bluetooth/hci_qca.c +++ b/drivers/bluetooth/hci_qca.c @@ -1080,7 +1080,7 @@ static int qca_set_speed(struct hci_uart *hu, enum qca_speed_type speed_type) { unsigned int speed, qca_baudrate; struct qca_serdev *qcadev; - int ret; + int ret = 0; if (speed_type == QCA_INIT_SPEED) { speed = qca_get_speed(hu, QCA_INIT_SPEED); @@ -1097,22 +1097,27 @@ static int qca_set_speed(struct hci_uart *hu, enum qca_speed_type speed_type) * the old speed. */ qcadev = serdev_device_get_drvdata(hu->serdev); - if (qcadev->btsoc_type == QCA_WCN3990) + if (qcadev->btsoc_type == QCA_WCN3990) { + hci_uart_set_flow_control(hu, true); serdev_device_set_rts(hu->serdev, false); + } qca_baudrate = qca_get_baudrate_value(speed); bt_dev_dbg(hu->hdev, "Set UART speed to %d", speed); ret = qca_set_baudrate(hu->hdev, qca_baudrate); if (ret) - return ret; + goto out; host_set_baudrate(hu, speed); - if (qcadev->btsoc_type == QCA_WCN3990) +out: + if (qcadev->btsoc_type == QCA_WCN3990) { + hci_uart_set_flow_control(hu, false); serdev_device_set_rts(hu->serdev, true); + } } - return 0; + return ret; } static int qca_wcn3990_init(struct hci_uart *hu)