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=-2.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,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 AAE28C43144 for ; Tue, 26 Jun 2018 18:32:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5848A26F0B for ; Tue, 26 Jun 2018 18:32:14 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="hFmOHGRj" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5848A26F0B 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-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932908AbeFZScM (ORCPT ); Tue, 26 Jun 2018 14:32:12 -0400 Received: from mail-pl0-f66.google.com ([209.85.160.66]:37310 "EHLO mail-pl0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754930AbeFZScJ (ORCPT ); Tue, 26 Jun 2018 14:32:09 -0400 Received: by mail-pl0-f66.google.com with SMTP id 31-v6so8954112plc.4 for ; Tue, 26 Jun 2018 11:32:08 -0700 (PDT) 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=k+FhrddAyK5AvpjIYUj5KEVi546GEyZaS3i8sWSRbsg=; b=hFmOHGRjS4HFuNOJLtNHFpeZ+CKROLGJyUvwAzRS7BY6e+91U1Jxfd6zfGJlWpMv1q tg8eeMc8Ys1jNrGFPoyquLRZqV8J8kxPTe3eQyEHBD+UNMKNsgOKTVcimxYfuXFY80Z0 B4TOMZzTez3kI6NKrL0fASMw4eLBH0VmLb+XQ= 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=k+FhrddAyK5AvpjIYUj5KEVi546GEyZaS3i8sWSRbsg=; b=CPFEDNx4jxGak37Qk/Yp12a6kDhIJCYOQPpvELVkZ2/lyUD75P2eQnt5HuhY+y/s9S fv/9W5DDDMzRQhsHvZ8N82pAaVtdW7zIRT6TxpE2Qz70ZGQ7g+yKdaTXop6U+tFd38hj fV7unhO6MrRlYEvoOGrraKp3nrFVMswMqTqeBxajGtZ7QwQX1PEBsEjPu6JMcYPFkaqo Y9+ee2+zud8SW7gIZS1aPKZETojZYLnDeOunUotqFKwS9m7zfHlHVYuu8NbgkhCy29Kz K/OZw8n1fyONziwG8bXGp0kk6NMifM1sQCD5Jgz/Kj5irOm96ubwn/wHBF648+urXQR+ rpCg== X-Gm-Message-State: APt69E1rjl1Pero9eKbA6qWWrnX5bc/JfhLMUQuWP45f9HP647rruSky kzT7PhDtmdsQHUra2Rgt7I8P1w== X-Google-Smtp-Source: ADUXVKKCi0Vy1ZTryySbwVzL2ZCx7hCdn8V4uMs40RlCeeT4HyQ0BNvHXWER2Rd2B80O2nN/k49XlQ== X-Received: by 2002:a17:902:b20d:: with SMTP id t13-v6mr2790564plr.121.1530037928649; Tue, 26 Jun 2018 11:32:08 -0700 (PDT) Received: from localhost ([2620:0:1000:1501:8e2d:4727:1211:622]) by smtp.gmail.com with ESMTPSA id r26-v6sm10858690pfj.180.2018.06.26.11.32.07 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Tue, 26 Jun 2018 11:32:08 -0700 (PDT) Date: Tue, 26 Jun 2018 11:32:07 -0700 From: Matthias Kaehlcke To: Balakrishna Godavarthi Cc: marcel@holtmann.org, johan.hedberg@gmail.com, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, linux-bluetooth@vger.kernel.org, rtatiya@codeaurora.org, hemantg@codeaurora.org, linux-arm-msm@vger.kernel.org Subject: Re: [PATCH v8 4/7] Bluetooth: hci_qca: Add wrapper functions for setting UART speed Message-ID: <20180626183207.GM129942@google.com> References: <20180625134013.19684-1-bgodavar@codeaurora.org> <20180625134013.19684-5-bgodavar@codeaurora.org> <20180625234354.GI129942@google.com> <20180626000529.GJ129942@google.com> <66681ee5281749e17394cab6f58083d8@codeaurora.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <66681ee5281749e17394cab6f58083d8@codeaurora.org> User-Agent: Mutt/1.9.2 (2017-12-15) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jun 26, 2018 at 10:43:31AM +0530, Balakrishna Godavarthi wrote: > Hi Matthias, > > On 2018-06-26 05:35, Matthias Kaehlcke wrote: > > On Mon, Jun 25, 2018 at 04:43:54PM -0700, Matthias Kaehlcke wrote: > > > This is a nice improvement, a few remaining questions inline. > > > > > > On Mon, Jun 25, 2018 at 07:10:10PM +0530, Balakrishna Godavarthi > > > wrote: > > > > In function qca_setup, we set initial and operating speeds for Qualcomm > > > > Bluetooth SoC's. This block of code is common across different > > > > Qualcomm Bluetooth SoC's. Instead of duplicating the code, created > > > > a wrapper function to set the speeds. So that future coming SoC's > > > > can use these wrapper functions to set speeds. > > > > > > > > Signed-off-by: Balakrishna Godavarthi > > > > --- > > > > Changes in v8: > > > > * common function to set INIT and operating speeds. > > > > * moved hardware flow control to qca_set_speed(). > > > > > > > > Changes in v7: > > > > * initial patch > > > > * created wrapper functions for init and operating speeds. > > > > --- > > > > drivers/bluetooth/hci_qca.c | 89 +++++++++++++++++++++++++++---------- > > > > 1 file changed, 65 insertions(+), 24 deletions(-) > > > > > > > > diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c > > > > index fe62420ef838..38b7dbe6c897 100644 > > > > --- a/drivers/bluetooth/hci_qca.c > > > > +++ b/drivers/bluetooth/hci_qca.c > > > > @@ -119,6 +119,11 @@ struct qca_data { > > > > u64 votes_off; > > > > }; > > > > > > > > +enum qca_speed_type { > > > > + QCA_INIT_SPEED = 1, > > > > + QCA_OPER_SPEED > > > > +}; > > > > + > > > > struct qca_serdev { > > > > struct hci_uart serdev_hu; > > > > struct gpio_desc *bt_en; > > > > @@ -923,6 +928,60 @@ static inline void host_set_baudrate(struct hci_uart *hu, unsigned int speed) > > > > hci_uart_set_baudrate(hu, speed); > > > > } > > > > > > > > +static unsigned int qca_get_speed(struct hci_uart *hu, > > > > + enum qca_speed_type speed_type) > > > > +{ > > > > + unsigned int speed = 0; > > > > + > > > > + if (speed_type == QCA_INIT_SPEED) { > > > > + if (hu->init_speed) > > > > + speed = hu->init_speed; > > > > + else if (hu->proto->init_speed) > > > > + speed = hu->proto->init_speed; > > > > + } else { > > > > + if (hu->oper_speed) > > > > + speed = hu->oper_speed; > > > > + else if (hu->proto->oper_speed) > > > > + speed = hu->proto->oper_speed; > > > > + } > > > > + > > > > + return speed; > > > > +} > > > > + > > > > +static int qca_set_speed(struct hci_uart *hu, enum qca_speed_type speed_type) > > > > +{ > > > > + unsigned int speed, qca_baudrate; > > > > + int ret; > > > > + > > > > + if (speed_type == QCA_INIT_SPEED) { > > > > + speed = qca_get_speed(hu, QCA_INIT_SPEED); > > > > + if (speed) > > > > + host_set_baudrate(hu, speed); > > > > + else > > > > + bt_dev_err(hu->hdev, "Init speed should be non zero"); > > > > > > The check for 'speed == 0' is done in multiple places. From this > > > code I deduce that it is expected that both INIT and OPER speed are > > > set to non-zero values. What happens if either of them is zero? Is the > > > driver still operational? > > > > > > > + return 0; > > > > + } > > > > + > > > > + speed = qca_get_speed(hu, QCA_OPER_SPEED); > > > > + if (!speed) { > > > > + bt_dev_err(hu->hdev, "operating speed should be non zero"); > > > > + return 0; > > > > + } > > > > + > > > > + qca_baudrate = qca_get_baudrate_value(speed); > > > > + bt_dev_info(hu->hdev, "Set UART speed to %d", speed); > > > > + ret = qca_set_baudrate(hu->hdev, qca_baudrate); > > > > + if (ret) { > > > > + bt_dev_err(hu->hdev, "Failed to change the baudrate (%d)", ret); > > > > + return ret; > > > > + } > > > > + > > > > + host_set_baudrate(hu, speed); > > > > + > > > > + return ret; > > > > +} > > > > > > In the discussion on "[v7,8/8] Bluetooth: hci_qca: Add support for > > > Qualcomm Bluetooth chip wcn3990" you mentioned the possbility to move > > > the hci_uart_set_flow_control() calls into _set_speed(). This seemed > > > interesting but finally it isn't done in this series. Did you > > > encounter that it is not feasible/desirable for some reason? > > > > I got that half wrong. "[v8,7/7] Bluetooth: hci_qca: Add support for > > Qualcomm Bluetooth chip wcn3990" adds the flow control calls to > > _set_speed() however there are still_set_flow_control() calls in > > qca_setup(), which confused/s me. > > > > Could you provide a brief summary on the situations (relevant for this > > driver) in which flow controls needs to be enabled/disabled? > > you will not find enable or disable of hardware flow control in this patch. > there is no hardware flow control in ROME chip. > you will find hardware flow control in wcn3990 i.e. patch [v8 7/7] Makes sense, when looking first at this I forgot the flow control handling was only added for wcn3990. > in wcn3990. we disable hardware flow control, when we sent mandatory > commands to BT chip. > > i.e while sending power on pulse i.e 0xFC byte for wcn3990 to boot up > completely and sending change baudrate request to BT chip. > before sending these commands, we disable the chip flow control and enable > flow control once we sent these commands. > > so in our current code after integrating wcn3990, we disable flow control > two times. > > 1. Before sending power on pulse i.e. qca_send_vendor_cmd(hdev, > QCA_WCN3990_POWERON_PULSE); in qca_setup. > so we find disable or enable hardware flow control in qca_setup() > 2. Before sending change BT CHIP baudrate request i.e. > qca_set_baudrate(hu->hdev, qca_baudrate); in qca_set_speed(). Thanks for the information! If there are more mandatory commands it could be an option to have a wrapper for them or do the flow control handling in qca_send_vendor_cmd() to avoid cluttering the main code path. Just an idea, no need to do this now.