439b87fceb
MLX90640 should ideally be working without a frame skip. In short, if a frame is skipped, then half of a frame loses correction information, having no way to retrieve its original compensation. This patch improves the timing in three ways: 1) Replaced schedule_timeout_interruptible() to usleep_range() The former "only ensures that it will sleep for at least schedule_delay (if not interrupted)", as pointed out by mchehab. As a result, the frame rate could lag behind than the actual capability of the hardware (Raspberry Pi would show a few Hz slower than set value) 2) Calculation based on us, not jiffies Jiffies usually has resolution of 100Hz, and possibly even cruder. MLX90640 can go up to 64Hz frame rate, which does not make sense to calculate the interval with aforementioned resolution. 3) Interval calculation based on the last frame's end time Using the start time of the current frame will probably make tiny bit of drift every time. This made more sense when I didn't realize 1), but it still makes sense without adding virtually any complexity, so this stays in. Signed-off-by: Seongyong Park <euphoriccatface@gmail.com> Acked-by: Matt Ranostay <matt.ranostay@konsulko.com> Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@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 Restructured Text 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.