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 35186C282C3 for ; Tue, 22 Jan 2019 21:39:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0349021726 for ; Tue, 22 Jan 2019 21:39:42 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="I7ccCNQT" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726765AbfAVVjk (ORCPT ); Tue, 22 Jan 2019 16:39:40 -0500 Received: from mail-pg1-f195.google.com ([209.85.215.195]:43282 "EHLO mail-pg1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726604AbfAVVjk (ORCPT ); Tue, 22 Jan 2019 16:39:40 -0500 Received: by mail-pg1-f195.google.com with SMTP id v28so7904pgk.10 for ; Tue, 22 Jan 2019 13:39:39 -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=s1uBC0RAdo9MQ/lPZMxofyh91Ty2fVmSBsf+/Kce4B4=; b=I7ccCNQTJeR/B00UEtaVVVLPfimVQBrZH+7e8THmRr/vOfi2AW5v6tYxBxogRxvTKv 3pUkDwLngBTOJvrv93uQFguYN9OYL4dhbbtHkomYMo1hyzHBbd8qJeHvzixHckrec0av u7Ic7zhhEW4YQj5y3A8ulf3vQI5/+RndW4cuM= 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=s1uBC0RAdo9MQ/lPZMxofyh91Ty2fVmSBsf+/Kce4B4=; b=b0skPiNETRmYxK4nlB/kYDRAsWZ14ktmtWYQDduwfgZ52gBc1Xvl38geVdmEtBcJwe hPJHm2h1ByjwtXSJeCNewurOKghB/EBgZ46oWAGrBjeWVt6+2z83Q7Rzi7E6I0P3jGxm TEiGKJyegkuU+0dAGbpLysDKB92ajvGKQyWHaecmLFyyOvDZCQ+oNWPyp6UCyXobVYZu cbQCh4rvXd8E2lEnMSDHesH9lZAmuTA3oY1318KVI7ZLC1FVVS1cdXoSfILq7+jICePD rwtS80MlW2/+DoTjVCckWJfdKY4ns4KSPaA+YA/CFc01dZFy/cp7ZO05I6ilAFMpzxCw im/Q== X-Gm-Message-State: AJcUukeWF4lgQlZf6e0DhDBGLahvZzXKmR6iD9gJAdfA2R7wtXm4JofR r+Zxv8XXVztLSUta0jDGoiHpSQ== X-Google-Smtp-Source: ALg8bN6S4YbWGdSGRk/8ODqL2gEzCmVditL8nDs3gWaxGr62p3HvTqrUU9WblIa3fWCt/D7rwBat0w== X-Received: by 2002:a62:4851:: with SMTP id v78mr35282757pfa.97.1548193178952; Tue, 22 Jan 2019 13:39:38 -0800 (PST) Received: from localhost ([2620:15c:202:1:75a:3f6e:21d:9374]) by smtp.gmail.com with ESMTPSA id b7sm22038119pfa.52.2019.01.22.13.39.37 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Tue, 22 Jan 2019 13:39:37 -0800 (PST) Date: Tue, 22 Jan 2019 13:39:36 -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: <20190122213936.GH261387@google.com> References: <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> <20190119003109.GD261387@google.com> <20190121085613.GG3691@localhost> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20190121085613.GG3691@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 Mon, Jan 21, 2019 at 09:56:13AM +0100, Johan Hovold wrote: > On Fri, Jan 18, 2019 at 04:31:09PM -0800, Matthias Kaehlcke wrote: > > 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/ > > Nice (I did mean set_mctrl() above, as I think you noticed). > > > 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); > > Wow, yeah, this parameter inversion is indeed confusing... > > > serdev_device_set_rts(hu->serdev, false); > > + } > > But looking at hci_uart_set_flow_control() now, it actually also > deasserts RTS. So all you need here is the hci_uart_set_flow_control() > call. Great, thanks for pointing that out! > And that makes the inversion make a bit more sense too, even if the > naming is a bit unfortunate with respect to > serdev_device_set_flow_control() at least.