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From:   Michael Rodin <mrodin@de.adit-jv.com>
To:     Mauro Carvalho Chehab <mchehab@kernel.org>,
        =?UTF-8?q?Niklas=20S=C3=B6derlund?= <niklas.soderlund@ragnatech.se>,
        <linux-media@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <linux-renesas-soc@vger.kernel.org>
CC:     Michael Rodin <mrodin@de.adit-jv.com>, <michael@rodin.online>,
        <erosca@de.adit-jv.com>
Subject: Improve error handling in the rcar-vin driver
Date:   Thu, 19 May 2022 20:00:06 +0200
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Hello,

this series is a followup to the other series [1] started by Niklas Söderlund
where only the first patch has been merged. The overall idea is to be more
compliant with the Renesas hardware manual which requires a reset or stop
of capture in the VIN module before reset of CSI2. Another goal (achieved
by the patch 3/3) is to be more resilient with respect to non-critical CSI2
errors so the driver does not end in an endless restart loop.

Patch 1/3 has been taken from [1] with some additional documentation changes.
Patch 2/3 is included without any changes.
Patch 3/3 is based on discussions in [2], where I also found one method to
trigger CSI2 errors in the video pipeline on a Salvator board for testing
by manipulating CSI2-related registers in the adv7482:

$ i2cset -f -y 4 0x64 0x00 0x04
$ i2cset -f -y 4 0x64 0x00 0x24

[1] https://lore.kernel.org/linux-renesas-soc/20211108160220.767586-1-niklas.soderlund+renesas@ragnatech.se/
[2] https://lore.kernel.org/linux-renesas-soc/20220309192707.GA62903@vmlxhi-121.adit-jv.com/