dfbfb7aa83
The clock rate, while hardcoded until now, is actually a function of the resolution, framerate and bytes per pixel. Now that we have an algorithm to adjust our clock rate, we can select it dynamically when we change the mode. This changes a bit the clock rate being used, with the following effect: +------+------+------+------+-----+-----------------+----------------+-----------+ | Hact | Vact | Htot | Vtot | FPS | Hardcoded clock | Computed clock | Deviation | +------+------+------+------+-----+-----------------+----------------+-----------+ | 640 | 480 | 1896 | 1080 | 15 | 56000000 | 61430400 | 8.84 % | | 640 | 480 | 1896 | 1080 | 30 | 112000000 | 122860800 | 8.84 % | | 1024 | 768 | 1896 | 1080 | 15 | 56000000 | 61430400 | 8.84 % | | 1024 | 768 | 1896 | 1080 | 30 | 112000000 | 122860800 | 8.84 % | | 320 | 240 | 1896 | 984 | 15 | 56000000 | 55969920 | 0.05 % | | 320 | 240 | 1896 | 984 | 30 | 112000000 | 111939840 | 0.05 % | | 176 | 144 | 1896 | 984 | 15 | 56000000 | 55969920 | 0.05 % | | 176 | 144 | 1896 | 984 | 30 | 112000000 | 111939840 | 0.05 % | | 720 | 480 | 1896 | 984 | 15 | 56000000 | 55969920 | 0.05 % | | 720 | 480 | 1896 | 984 | 30 | 112000000 | 111939840 | 0.05 % | | 720 | 576 | 1896 | 984 | 15 | 56000000 | 55969920 | 0.05 % | | 720 | 576 | 1896 | 984 | 30 | 112000000 | 111939840 | 0.05 % | | 1280 | 720 | 1892 | 740 | 15 | 42000000 | 42002400 | 0.01 % | | 1280 | 720 | 1892 | 740 | 30 | 84000000 | 84004800 | 0.01 % | | 1920 | 1080 | 2500 | 1120 | 15 | 84000000 | 84000000 | 0.00 % | | 1920 | 1080 | 2500 | 1120 | 30 | 168000000 | 168000000 | 0.00 % | | 2592 | 1944 | 2844 | 1944 | 15 | 84000000 | 165862080 | 49.36 % | +------+------+------+------+-----+-----------------+----------------+-----------+ Only the 640x480, 1024x768 and 2592x1944 modes are significantly affected by the new formula. In this case, 640x480 and 1024x768 are actually fixed by this change. Indeed, the sensor was sending data at, for example, 27.33fps instead of 30fps. This is -9%, which is roughly what we're seeing in the array. Testing these modes with the new clock setup actually fix that error, and data are now sent at around 30fps. 2592x1944, on the other hand, is probably due to the fact that this mode can only be used using MIPI-CSI2, in a two lane mode, and never really tested with a DVP bus. Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com> Tested-by: Adam Ford <aford173@gmail.com> #imx6dq Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com> Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@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.