From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <SRS0=/KXw=BJ=vger.kernel.org=linux-tegra-owner@kernel.org>
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=-6.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH,
	DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,
	MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,
	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 5793CC433E3
	for <linux-tegra@archiver.kernel.org>; Thu, 30 Jul 2020 00:40:13 +0000 (UTC)
Received: from vger.kernel.org (vger.kernel.org [23.128.96.18])
	by mail.kernel.org (Postfix) with ESMTP id 36DBB2074B
	for <linux-tegra@archiver.kernel.org>; Thu, 30 Jul 2020 00:40:13 +0000 (UTC)
Authentication-Results: mail.kernel.org;
	dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="DGoWzp8Y"
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S1727862AbgG3AkI (ORCPT <rfc822;linux-tegra@archiver.kernel.org>);
        Wed, 29 Jul 2020 20:40:08 -0400
Received: from hqnvemgate25.nvidia.com ([216.228.121.64]:3294 "EHLO
        hqnvemgate25.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
        with ESMTP id S1727858AbgG3AkI (ORCPT
        <rfc822;linux-tegra@vger.kernel.org>);
        Wed, 29 Jul 2020 20:40:08 -0400
Received: from hqpgpgate101.nvidia.com (Not Verified[216.228.121.13]) by hqnvemgate25.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA)
        id <B5f2216ba0000>; Wed, 29 Jul 2020 17:39:22 -0700
Received: from hqmail.nvidia.com ([172.20.161.6])
  by hqpgpgate101.nvidia.com (PGP Universal service);
  Wed, 29 Jul 2020 17:40:08 -0700
X-PGP-Universal: processed;
        by hqpgpgate101.nvidia.com on Wed, 29 Jul 2020 17:40:08 -0700
Received: from [10.2.160.194] (10.124.1.5) by HQMAIL107.nvidia.com
 (172.20.187.13) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Thu, 30 Jul
 2020 00:40:07 +0000
Subject: Re: [RFC PATCH v5 13/14] media: tegra-video: Add CSI MIPI pads
 calibration
From:   Sowjanya Komatineni <skomatineni@nvidia.com>
To:     Dmitry Osipenko <digetx@gmail.com>, <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: <1595883452-17343-1-git-send-email-skomatineni@nvidia.com>
 <1595883452-17343-14-git-send-email-skomatineni@nvidia.com>
 <c3d40261-9d77-3634-3e04-f20efad9d3d8@gmail.com>
 <01ee0805-3d57-d857-48e3-5c2245cd4500@nvidia.com>
 <2ec535c9-55e8-8834-6002-36c75aeb097c@gmail.com>
 <021707b9-5f72-6f8b-d125-43627ef64a6d@nvidia.com>
 <de2d6117-b1e5-14c0-52ca-ff46b444c866@nvidia.com>
Message-ID: <5d2b67a1-9e85-606e-9bf2-802379d922f9@nvidia.com>
Date:   Wed, 29 Jul 2020 17:47:23 -0700
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: <de2d6117-b1e5-14c0-52ca-ff46b444c866@nvidia.com>
X-Originating-IP: [10.124.1.5]
X-ClientProxiedBy: HQMAIL111.nvidia.com (172.20.187.18) To
 HQMAIL107.nvidia.com (172.20.187.13)
Content-Type: text/plain; charset="utf-8"; format=flowed
Content-Transfer-Encoding: quoted-printable
Content-Language: en-US
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1;
        t=1596069562; bh=zEElWQxu+E1s3hgsmMljlq5NeoGb/HDShunRfurBl1o=;
        h=X-PGP-Universal:Subject:From:To:CC:References:Message-ID:Date:
         User-Agent:MIME-Version:In-Reply-To:X-Originating-IP:
         X-ClientProxiedBy:Content-Type:Content-Transfer-Encoding:
         Content-Language;
        b=DGoWzp8YtSe4A/xQLbriAj7OL91uXQOIF5J0MKiXJ8xV1YVHnCtbKakSezHOvNF02
         Xd7n0dQRTb4x+22UaD6YcUUoFzivv9Ixu1Au1jLIhTBYegh0Mp8DL5qhNCvNXEpU8H
         VGmFd4k8azuwtWHffTepbkizahAl3lQLN/hUzIM3pPwxUJLrZB4ppZXQYBm5rTrXKu
         UmAyBLIKLtnrpf95GSk/x6tLa2iODe2pYYQArMExus1wnF10KuamfSJ/YcvIuSOsCD
         ZJVZhmnRk759y9zzE7jbO4YyTFCKngOgO+chWECcyaIuiTbx9eYvsrqqhbFNkoUtw/
         s14adilLiiWlA==
Sender: linux-tegra-owner@vger.kernel.org
Precedence: bulk
List-ID: <linux-tegra.vger.kernel.org>
X-Mailing-List: linux-tegra@vger.kernel.org


On 7/29/20 5:27 PM, Sowjanya Komatineni wrote:
>
> On 7/29/20 4:59 PM, Sowjanya Komatineni wrote:
>>
>> On 7/29/20 4:25 PM, Dmitry Osipenko wrote:
>>> 28.07.2020 18:59, Sowjanya Komatineni =D0=BF=D0=B8=D1=88=D0=B5=D1=82:
>>> ...
>>>>>> +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 ret =3D tegra_mipi_finis=
h_calibration(csi_chan->mipi);
>>>>>> +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 if (ret < 0)
>>>>>> +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 =
dev_err(csi_chan->csi->dev,
>>>>>> +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=
=C2=A0=C2=A0=C2=A0=C2=A0 "MIPI calibration failed: %d\n", ret);
>>>>> Doesn't v4l2_subdev_call(OFF) need to be invoked here on error?
>>>> Not required as on error streaming fails and runtime PM will turn off
>>>> power anyway.
>>> I see that camera drivers bump theirs RPM on s_stream=3D1, and thus,
>>> s_stream=3D0 should be invoked in order to balance the RPM. What am I=20
>>> missing?
>>>
>>> https://elixir.bootlin.com/linux/v5.8-rc4/source/drivers/media/i2c/ov27=
40.c#L634=20
>>>
>>
>> Sensor drivers take care of RPM put when any failure happens during=20
>> s_stream.
>>
>> So bridge driver don't have to call v4l2_subdev_call s_stream off=20
>> incase if sensor subdev stream on fails.
>>
>>>> Also we only did csi subdev s_stream on and during sensor subdev
>>>> s_stream on fail, actual stream dont happen and on tegra side frame
>>>> capture by HW happens only when kthreads run.
>>> Secondly, perhaps a failed calibration isn't a very critical error?
>>> Hence just printing a warning message should be enough.
>>
>> Using dev_err to report calibration failure. Are you suggesting to=20
>> use dev_warn instead of dev_err?
>>
OK I think I understood what you meant.

When v4l2_subdev_call for sensor s_stream ON fails, we dont have to do=20
v4l2_subdev_call s_stream OFF.

As sensor drivers take care of RPM put when any failure happens during=20
s_stream ON

Other case when v4l2_subdev_call for sensor s_stream ON is good, then=20
tegra_mipi_finish_calibration fail need to call s_stream OFF for sensor.

Agree as calibration errors out in this case as its not critical in this=20
scenario, So will change dev_err to dev_warn and will not report this as=20
error so no need to call s_stream off.

>>>
>>> Could you please make a patch that factors all ON/OFF code paths into a
>>> separate functions? It's a bit difficult to follow the combined code,
>>> especially partial changes in the patches. Thanks in advance!
>>
>> what do you mean by partial changes in patches?
>>
>> Can you please be more clear?
>
> Also please specify what ON/OFF code paths you are referring to when=20
> you say to move into separate functions?
>
>>
>> Thanks
>>
>> Sowjanya
>>