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Niklas Söderlund
a67e0eed50
The s_power callback is used a bit oddly in adv7180, the callback adv7180_set_power() do not control power to the chip itself, but rather the power to the chips decoder. When the decoder is powered the chip process video data, or if no video source is available freeruns. When the decoder is off the device i2c registers are still powered and the device can be configured. In the current s_power implementation the device starts to transmit video data as soon as it's powered, and the s_stream operation only tracks if s_stream have been called or not. The actual configuration of the device happens when the configuration IOCTLs are called. Sometimes with very odd implementations where the decoder have to first be power off, the device configured, and then unconditionally power on, see adv7180_set_pad_format() for an example. As a first step to remedy this remove the s_power callback altogether and instead completely initialize the device from s_stream. Future work will clean up the IOCTL callbacks that directly configures the device that is also done by init_device(). Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se> Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.