c8d4a56082
The video DSI mode had not really been tested. These fixes makes
it more likely to work on real hardware:
- Put the active width (x width) in the right bits and the VSA
(vertical sync active) in the right bits (those were swapped).
- Calculate the packet sizes in bytes as in the vendor driver,
rather than in bits. Test the calculations agains a
spreadsheet and confirmed by debug prints to be reasonable.
- Also verified the register values with relative confidence
to register dumps from the Samsung GT-I8190 boot loader
graphics. We are not identical but not off by far either.
- Error out if the current mode and refresh frequency doesn't
work out. (In the future we may simply want to scale down
the vrefresh.)
- Handle negative result in front/back/sync packages and fall
back to zero like in the vendor driver.
- Put in lots of clarifying comments and references to the
documentation where the code is hard to understand.
- Set the DSI_VID_VCA_SETTING2 field
DSI_VID_VCA_SETTING2_MAX_LINE_LIMIT to blkline_pck - 6 as in
the vendor driver and mask the field properly.
- Set the DSI_VID_VCA_SETTING1 field
DSI_VID_VCA_SETTING1_MAX_BURST_LIMIT to blkeol_pck - 6 to
blkeol_duration - 6 as in the vendor driver.
Cc: Stephan Gerhold <stephan@gerhold.net>
Fixes: 5fc537bfd000 ("drm/mcde: Add new driver for ST-Ericsson MCDE")
Link: https://patchwork.freedesktop.org/patch/msgid/20191217150959.17215-1-linus.walleij@linaro.org
Reviewed-by: Stephan Gerhold <stephan@gerhold.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.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.