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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT 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 6FE33C43441 for ; Mon, 26 Nov 2018 19:42:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2B65420855 for ; Mon, 26 Nov 2018 19:42:20 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="PChYuc5x" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2B65420855 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=chromium.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-bluetooth-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726513AbeK0GhW (ORCPT ); Tue, 27 Nov 2018 01:37:22 -0500 Received: from mail-pf1-f196.google.com ([209.85.210.196]:41599 "EHLO mail-pf1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726414AbeK0GhW (ORCPT ); Tue, 27 Nov 2018 01:37:22 -0500 Received: by mail-pf1-f196.google.com with SMTP id b7so7080467pfi.8 for ; Mon, 26 Nov 2018 11:42:12 -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=8k2YtHI7XBnd3/667SiR7CshYKJKmltQZinOc/YlDxQ=; b=PChYuc5xK1m2QUjJ6faPzhQ41GTEr+dr4znwHpoHbubWRpuZ4X0Dp0O2IZLiXXhLBv aNVPUz46zNW2nZzfxf58ifyCWnQ3he2PC0Md03pFvFpFLlK/Fuj3lWxbdFt5tC9F/X3u GfxkyTMfIP4ggztbxSVlziGsEDhjkG2dsgEfA= 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=8k2YtHI7XBnd3/667SiR7CshYKJKmltQZinOc/YlDxQ=; b=L4z+yKVfTl9cdW/zXH8aGjEapcgL8m/VIuYNzXw1a6uum8IjwavT88DbcGra3pf7Mn 9NZp5LtsKzZdmTPrukJQMDZg4G9YgrUZqDlyyLbIiBM/yX3A5713G4QwDMaDUyEV1Zo9 WEszFPIOj838XwQvbsLZTDHhPxGmy8d7xU/UWHGwuEzFQE0hH33hypmsqjdDL1eDVT2v Mo+Vxz6Djs5PlPNs0pS3B6glD9doyce1itpFBLFukcfFzERADjd3cmGddU1XW0VK+rda L/kWyx4YRVMm2E7PFnP0jsDrEePjeIEZXlGMpRVJ03YWczvmDIpZAUmzJLq+JDa1cqsx apkA== X-Gm-Message-State: AA+aEWa77pI+11CrVKsxEzzQoaMNcfFXIApr3GkXN+/w8F3GfdRcDbUF TYzw1+oOG0SerNFcdgim8o3R/A== X-Google-Smtp-Source: AFSGD/UgJ5a6X6tdX98vvjDVT2vPvLNkzL81Muvg/SekmsMPuK/09DDjIR2AuWag1GqJ0Xmm4psArg== X-Received: by 2002:a63:91c1:: with SMTP id l184mr26373176pge.29.1543261332108; Mon, 26 Nov 2018 11:42:12 -0800 (PST) Received: from localhost ([2620:15c:202:1:b6af:f85:ed6c:ac6a]) by smtp.gmail.com with ESMTPSA id n2sm1156710pgp.75.2018.11.26.11.42.11 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Mon, 26 Nov 2018 11:42:11 -0800 (PST) Date: Mon, 26 Nov 2018 11:42:10 -0800 From: Matthias Kaehlcke To: Balakrishna Godavarthi Cc: 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 Subject: Re: [PATCH v2 2/3] Bluetooth: hci_qca: Deassert RTS while baudrate change command Message-ID: <20181126194210.GW22824@google.com> References: <20181122121512.13136-1-bgodavar@codeaurora.org> <20181122121512.13136-3-bgodavar@codeaurora.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20181122121512.13136-3-bgodavar@codeaurora.org> User-Agent: Mutt/1.9.2 (2017-12-15) Sender: linux-bluetooth-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-bluetooth@vger.kernel.org On Thu, Nov 22, 2018 at 05:45:11PM +0530, Balakrishna Godavarthi wrote: > This patch will help to stop frame reassembly errors while changing > the baudrate. This is because host send a change baudrate request > command to the chip with 115200 bps, Whereas chip will change their > UART clocks to the enable for new baudrate and sends the response > for the change request command with newer baudrate, On host side > we are still operating in 115200 bps which results of reading garbage > data. Here we are pulling RTS line, so that chip we will wait to send data > to host until host change its baudrate. Thanks for updating the commit message and provide more details! > Signed-off-by: Balakrishna Godavarthi > Tested-by: Matthias Kaehlcke > --- > v2: > * updated commit text and comments. > v1: > * initial patch > --- > drivers/bluetooth/hci_qca.c | 23 ++++++++++++----------- > 1 file changed, 12 insertions(+), 11 deletions(-) > > diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c > index f5dd323c1967..ed905ea1c58a 100644 > --- a/drivers/bluetooth/hci_qca.c > +++ b/drivers/bluetooth/hci_qca.c > @@ -963,7 +963,6 @@ static int qca_set_baudrate(struct hci_dev *hdev, uint8_t baudrate) > struct hci_uart *hu = hci_get_drvdata(hdev); > struct qca_data *qca = hu->priv; > struct sk_buff *skb; > - struct qca_serdev *qcadev; > u8 cmd[] = { 0x01, 0x48, 0xFC, 0x01, 0x00 }; > > if (baudrate > QCA_BAUDRATE_3200000) > @@ -977,13 +976,6 @@ static int qca_set_baudrate(struct hci_dev *hdev, uint8_t baudrate) > return -ENOMEM; > } > > - /* Disabling hardware flow control is mandatory while > - * sending change baudrate request to wcn3990 SoC. > - */ > - qcadev = serdev_device_get_drvdata(hu->serdev); > - if (qcadev->btsoc_type == QCA_WCN3990) > - hci_uart_set_flow_control(hu, true); > - > /* Assign commands to change baudrate and packet type. */ > skb_put_data(skb, cmd, sizeof(cmd)); > hci_skb_pkt_type(skb) = HCI_COMMAND_PKT; > @@ -999,9 +991,6 @@ static int qca_set_baudrate(struct hci_dev *hdev, uint8_t baudrate) > schedule_timeout(msecs_to_jiffies(BAUDRATE_SETTLE_TIMEOUT_MS)); > set_current_state(TASK_RUNNING); > > - if (qcadev->btsoc_type == QCA_WCN3990) > - hci_uart_set_flow_control(hu, false); > - > return 0; > } > > @@ -1086,6 +1075,7 @@ static int qca_check_speeds(struct hci_uart *hu) > 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; > > if (speed_type == QCA_INIT_SPEED) { > @@ -1097,6 +1087,14 @@ static int qca_set_speed(struct hci_uart *hu, enum qca_speed_type speed_type) > if (!speed) > return 0; > > + /* Deassert RTS while changing the baudrate of chip and host. > + * This will stop chip to transmit it response with an newer > + * baudrate until we change the baudarte. nit: baudrate re-nit (to consider if you respin anyway): 'This prevents the chip from transmitting its response with the new baudrate while the host port is still operating at the old speed'? (I'm not a native English speaker, probably there is still room for improvement ;-) Reviewed-by: Matthias Kaehlcke