1284365e3e
The HVS Composite Output Buffer (COB) is the memory used to
generate the output pixel data.
Until now the vc4 driver has been relying on the firmware to
have set these to sensible values.
In testing triple screen support it has been noted that only
1 line was being assigned to HVS channel 2. Whilst that is fine
for the transposer (TXP), and indeed needed as only some pixels
have an alpha channel, it is insufficient to run a live display.
Split the COB more evenly between the 3 HVS channels.
Fixes: c54619b0bfb3 ("drm/vc4: Add support for the BCM2711 HVS5")
Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Link: https://lore.kernel.org/r/20221207-rpi-hvs-crtc-misc-v1-1-1f8e0770798b@cerno.tech
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
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.