Linux-i2c Archive on lore.kernel.org
 help / color / Atom feed
From: Dmitry Osipenko <digetx@gmail.com>
To: Sowjanya Komatineni <skomatineni@nvidia.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
Subject: Re: [RFC PATCH v6 09/10] media: tegra-video: Add CSI MIPI pads calibration
Date: Fri, 31 Jul 2020 19:14:36 +0300
Message-ID: <a08af0e8-80d8-0bd0-87a3-adfc8e70a92a@gmail.com> (raw)
In-Reply-To: <f483329d-b5fe-fda5-e235-b8edb5fce440@nvidia.com>

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".

  reply index

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-31  9:02 [RFC PATCH v6 00/10] Support for Tegra video capture from external sensor Sowjanya Komatineni
2020-07-31  9:02 ` [RFC PATCH v6 01/10] media: tegra-video: Fix channel format alignment Sowjanya Komatineni
2020-07-31  9:02 ` [RFC PATCH v6 02/10] media: tegra-video: Enable TPG based on kernel config Sowjanya Komatineni
2020-07-31  9:02 ` [RFC PATCH v6 03/10] media: tegra-video: Update format lookup to offset based Sowjanya Komatineni
2020-07-31  9:02 ` [RFC PATCH v6 04/10] dt-bindings: tegra: Update VI and CSI bindings with port info Sowjanya Komatineni
2020-07-31  9:02 ` [RFC PATCH v6 05/10] media: tegra-video: Separate CSI stream enable and disable implementations Sowjanya Komatineni
2020-07-31 12:06   ` Dmitry Osipenko
2020-07-31  9:02 ` [RFC PATCH v6 06/10] media: tegra-video: Add support for external sensor capture Sowjanya Komatineni
2020-07-31  9:02 ` [RFC PATCH v6 07/10] media: tegra-video: Add support for selection ioctl ops Sowjanya Komatineni
2020-07-31  9:02 ` [RFC PATCH v6 08/10] gpu: host1x: mipi: Keep MIPI clock enabled till calibration is done Sowjanya Komatineni
2020-07-31  9:02 ` [RFC PATCH v6 09/10] media: tegra-video: Add CSI MIPI pads calibration Sowjanya Komatineni
2020-07-31 11:39   ` Dmitry Osipenko
2020-07-31 15:46     ` Sowjanya Komatineni
2020-07-31 16:14       ` Dmitry Osipenko [this message]
2020-07-31 16:29         ` Sowjanya Komatineni
2020-07-31  9:02 ` [RFC PATCH v6 10/10] media: tegra-video: Compute settle times based on the clock rate Sowjanya Komatineni
2020-07-31 13:40 ` [RFC PATCH v6 00/10] Support for Tegra video capture from external sensor Wolfram Sang
2020-07-31 15:49   ` Sowjanya Komatineni

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=a08af0e8-80d8-0bd0-87a3-adfc8e70a92a@gmail.com \
    --to=digetx@gmail.com \
    --cc=devicetree@vger.kernel.org \
    --cc=frankc@nvidia.com \
    --cc=gregkh@linuxfoundation.org \
    --cc=helen.koike@collabora.com \
    --cc=hverkuil@xs4all.nl \
    --cc=jonathanh@nvidia.com \
    --cc=linux-i2c@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-media@vger.kernel.org \
    --cc=linux-tegra@vger.kernel.org \
    --cc=robh+dt@kernel.org \
    --cc=sakari.ailus@iki.fi \
    --cc=sboyd@kernel.org \
    --cc=skomatineni@nvidia.com \
    --cc=thierry.reding@gmail.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-i2c Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-i2c/0 linux-i2c/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-i2c linux-i2c/ https://lore.kernel.org/linux-i2c \
		linux-i2c@vger.kernel.org
	public-inbox-index linux-i2c

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-i2c


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git