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=-6.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 50D27C433DF for ; Fri, 31 Jul 2020 16:14:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2BBFD208E4 for ; Fri, 31 Jul 2020 16:14:44 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="tqEyFacW" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731559AbgGaQOl (ORCPT ); Fri, 31 Jul 2020 12:14:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38608 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728882AbgGaQOk (ORCPT ); Fri, 31 Jul 2020 12:14:40 -0400 Received: from mail-lj1-x243.google.com (mail-lj1-x243.google.com [IPv6:2a00:1450:4864:20::243]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 22BA6C061574; Fri, 31 Jul 2020 09:14:40 -0700 (PDT) Received: by mail-lj1-x243.google.com with SMTP id q4so33003760lji.2; Fri, 31 Jul 2020 09:14:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=YqMA8MeVxar9xICWh2YYRA4Gnd/k8GNWBNgCmBw99tA=; b=tqEyFacWSDK3UrI52boiLHw2n1BPJ4Srrxm/v0jx+fGs5nP2OSvk0dVD+/+Lq4ZxYw d/kAoS9TIkdBlGTisSTgAXxUPyur69lj5f/hO9wj0GHnTqijJS4TFYvqXgK557sg64vV EMysJSc4lAVqrYcCItYj7CtgM4wfIqmIfdobgVKlDa1rqZ7KsCaKhHRXH0Xrv0ePnHSv d93T8X8TxMS1JZALSQHKPdGP85yDiPDHWSNOgmjVj9JPmmBHEL/2bXYwvCMqiqb2C0YA O0TtFnAvU8+Z6N/mYVVNMP+e35TZoAjJyBh/zIs+X7PCttETymTC0R4vSf/yTshHio1o xM8Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=YqMA8MeVxar9xICWh2YYRA4Gnd/k8GNWBNgCmBw99tA=; b=gd6rDG1Z0QlzXjPrSIyvWY/iWEGmhvHc+vjQRmQwqGPiUYOHW4Jt/l25hIgne1pNlx l1Yhgfkp7YbTE9IeiXV9UelNSGeMfuo2fu3U+plLhL/Vxk2cZlc597oD9zMWpl+bhri+ saHhZfp1zrRxJr4IFw+BgpuWWCzkNf+1MpB5wwz3qw4yYr+ZlV9n78ZToD1blyjKf9vo nIalX12xuDDIVNUv5FCwMUEONMuwVBAU/mDoHKHk11MzpHRRA26/Um9BqhbxM/Pa0ZkN 9buzDM69JsayDS3GKn2FL8ma1BGNZ5C2A14pW31WRuzpaEMhO1zzRO+BnRj1B53pNR3l O1SQ== X-Gm-Message-State: AOAM530bSQ4PDq3GjpsbH5vdCuepwEyZ99/9GbyNn+UdY2QXIqsND4HX iYMOpZodGDv9/F82rcS4YNP9T5SE X-Google-Smtp-Source: ABdhPJw0T9d6zBh79kx3CAECrhIJjV4ghrzyu1L0Z953EnYBevf+69nMTDav1jQp8wWhyH+MgaARCA== X-Received: by 2002:a2e:b4b8:: with SMTP id q24mr2283271ljm.125.1596212078182; Fri, 31 Jul 2020 09:14:38 -0700 (PDT) Received: from [192.168.2.145] (94-29-41-50.dynamic.spd-mgts.ru. [94.29.41.50]) by smtp.googlemail.com with ESMTPSA id d26sm2038703lfq.73.2020.07.31.09.14.36 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 31 Jul 2020 09:14:37 -0700 (PDT) Subject: Re: [RFC PATCH v6 09/10] media: tegra-video: Add CSI MIPI pads calibration To: Sowjanya Komatineni , thierry.reding@gmail.com, jonathanh@nvidia.com, frankc@nvidia.com, hverkuil@xs4all.nl, sakari.ailus@iki.fi, robh+dt@kernel.org, helen.koike@collabora.com Cc: sboyd@kernel.org, gregkh@linuxfoundation.org, linux-media@vger.kernel.org, devicetree@vger.kernel.org, linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org, linux-i2c@vger.kernel.org References: <1596186169-18729-1-git-send-email-skomatineni@nvidia.com> <1596186169-18729-10-git-send-email-skomatineni@nvidia.com> <3ac158c4-7df7-e3c1-f0e1-33e7ef017762@gmail.com> From: Dmitry Osipenko Message-ID: Date: Fri, 31 Jul 2020 19:14:36 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org 31.07.2020 18:46, Sowjanya Komatineni пишет: > > On 7/31/20 4:39 AM, Dmitry Osipenko wrote: >> 31.07.2020 12:02, Sowjanya Komatineni пишет: >> ... >>> @@ -249,13 +249,47 @@ static int tegra_csi_enable_stream(struct >>> v4l2_subdev *subdev) >>>           return ret; >>>       } >>>   +    if (csi_chan->mipi) { >>> +        ret = tegra_mipi_enable(csi_chan->mipi); >>> +        if (ret < 0) { >>> +            dev_err(csi->dev, >>> +                "failed to enable MIPI pads: %d\n", ret); >>> +            goto rpm_put; >>> +        } >>> + >>> +        /* >>> +         * CSI MIPI pads PULLUP, PULLDN and TERM impedances need to >>> +         * be calibrated after power on. >>> +         * So, trigger the calibration start here and results will >>> +         * be latched and applied to the pads when link is in LP11 >>> +         * state during start of sensor streaming. >>> +         */ >>> +        ret = tegra_mipi_start_calibration(csi_chan->mipi); >>> +        if (ret < 0) { >>> +            dev_err(csi->dev, >>> +                "failed to start MIPI calibration: %d\n", ret); >>> +            goto disable_mipi; >>> +        } >> What would happen if CSI stream is enabled and then immediately disabled >> without enabling camera sensor? > > Nothing will happen as during stream enable csi receiver is kept ready. > > But actual capture will not happen during that point. Could you please show how the full call chain looks like? It's not clear to me what keeps CSI stream "ready".