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=-9.2 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=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 EFFA5C43441 for ; Wed, 14 Nov 2018 01:55:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A41CB2175B for ; Wed, 14 Nov 2018 01:55:08 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="GwYppH7D" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A41CB2175B 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 S1732014AbeKNL4H (ORCPT ); Wed, 14 Nov 2018 06:56:07 -0500 Received: from mail-pl1-f194.google.com ([209.85.214.194]:33986 "EHLO mail-pl1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731940AbeKNL4H (ORCPT ); Wed, 14 Nov 2018 06:56:07 -0500 Received: by mail-pl1-f194.google.com with SMTP id f12-v6so6967613plo.1 for ; Tue, 13 Nov 2018 17:55:06 -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=mkDhlP+vnX9nlcZ05WMCnjnXQtdM1dvqSuPMuNK8H8g=; b=GwYppH7DxBaANVuE/9CpvdsInLaNmJUFdk5cDHduveMa85uwtv1/SLEZTs4gphalpA tqHrJqGwpX72t+N8TTArvjyv9svJ3t9cEu0qGfofuqoN4cMmXoj7bJbG6/xAlSnG7ew6 9LzPQL2OTcnNkGPVI4bZQJ43sc9bUBFaZx/J0= 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=mkDhlP+vnX9nlcZ05WMCnjnXQtdM1dvqSuPMuNK8H8g=; b=QG2g84SJaNfmlHbyEdPi39ME6dpn4rc2sqJi6nCgg5OdqJZvwPvpW/hPklJw46zacr E8ZIdPltLDMGdepHdMJCYRSFhOm5r6qAWjp1hCOmvdqqmjTLtG6HR15F1zgr4QXISMMV piFzsJSlw99iRiuyHPO+OoRP3mFebTghPhDwydLpT+kbYaq3p0K4/u00qAH9xJo8ctEb h9a2EXNovqoNxU7FCR0HjD/8vmV1Jt99jxDibui3apM49BCCHjJ5Pj0SomDEXvZCn8Xo OIaUbTkfzlYA2Huxkx1UP9+DgbvJlLF1vX32O27MiQS0yI4EPjraVEkH4KESJnardHvm aY8Q== X-Gm-Message-State: AGRZ1gJw5heAe5z70yObuMjjYn2JRZCsYLd5PoBs6DAk2SE/kWpTgSTd 0aRgQYEiZ5HB0QbG5WHaWxwWVw== X-Google-Smtp-Source: AJdET5ehskN547xGoFPBB3qc2LzXzISQGt6bpnAqoIuRkU7XV/ZO0XPlWjp9WjYMVpZCTd5gZetDCA== X-Received: by 2002:a17:902:bd8e:: with SMTP id q14mr3195633pls.146.1542160506513; Tue, 13 Nov 2018 17:55:06 -0800 (PST) Received: from localhost ([2620:15c:202:1:b6af:f85:ed6c:ac6a]) by smtp.gmail.com with ESMTPSA id q195sm21810305pgq.7.2018.11.13.17.55.05 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Tue, 13 Nov 2018 17:55:05 -0800 (PST) Date: Tue, 13 Nov 2018 17:55:04 -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 v1 2/4] Bluetooth: hci_qca: Pull RTS line high for baudrate change command Message-ID: <20181114015504.GH22824@google.com> References: <20181106120528.30342-1-bgodavar@codeaurora.org> <20181106120528.30342-3-bgodavar@codeaurora.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20181106120528.30342-3-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 Tue, Nov 06, 2018 at 05:35:26PM +0530, Balakrishna Godavarthi wrote: > This patch will pull the RTS line high instead of turning off the > flow control, while changing baudrate of host and chip. Please don't only describe what is changed, but also why this change is necessary. IIUC the BT chip honors flow control during baudrate changes, however it sometimes sends 'garbage' which results in "Bluetooth: hci0: Frame reassembly failed (-84)" messages. > Signed-off-by: Balakrishna Godavarthi > --- > 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 051f081d1835..8301663f0004 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; > > + /* Pulling RTS line to high is mandatory while sending change > + * baudrate request to SoC and also while setting the host > + * baudrate. > + */ Instead of just stating that this is 'mandatory' explain why it is needed. Also better say 'Deassert RTS' instead of the more lower level 'Pulling RTS line to high'. It could be something like 'Deassert RTS to prevent the BT controller from sending garbage during the baudrate change.' > + qcadev = serdev_device_get_drvdata(hu->serdev); > + if (qcadev->btsoc_type == QCA_WCN3990) > + 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); > @@ -1104,6 +1102,9 @@ static int qca_set_speed(struct hci_uart *hu, enum qca_speed_type speed_type) > return ret; > > host_set_baudrate(hu, speed); > + > + if (qcadev->btsoc_type == QCA_WCN3990) > + serdev_device_set_rts(hu->serdev, true); > } > > return 0; Tested-by: Matthias Kaehlcke