a21906ead6
Underruns happens when plane height + y offset is not a modulo of 4 when FBC is enabled. It happens when scanline is at vactive - 10 but that is not feasible to do from the software side so here completely disabling FBC when height + y offset matches to avoid visual glitches. Specification says that it only affects TGL display C stepping and newer but to simply the check and as TGL is already in final costumers hands, pre-production display stepping A and B was also included. BSpec: 52887 ICL BSpec: 52888 EHL/JSL BSpec: 52890/55378 TGL BSpec: 53508 DG1 BSpec: 53273 RKL Signed-off-by: José Roberto de Souza <jose.souza@intel.com> Reviewed-by: Matt Roper <matthew.d.roper@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20201019175609.28715-1-jose.souza@intel.com
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.