778283dc28
commit a3f781a9d6114c1d1e01defb7aa234dec45d2a5f upstream. Add a config option CONFIG_FRAMEBUFFER_CONSOLE_LEGACY_ACCELERATION to enable bitblt and fillrect hardware acceleration in the framebuffer console. If disabled, such acceleration will not be used, even if it is supported by the graphics hardware driver. If you plan to use DRM as your main graphics output system, you should disable this option since it will prevent compiling in code which isn't used later on when DRM takes over. For all other configurations, e.g. if none of your graphic cards support DRM (yet), DRM isn't available for your architecture, or you can't be sure that the graphic card in the target system will support DRM, you most likely want to enable this option. In the non-accelerated case (e.g. when DRM is used), the inlined fb_scrollmode() function is hardcoded to return SCROLL_REDRAW and as such the compiler is able to optimize much unneccesary code away. In this v3 patch version I additionally changed the GETVYRES() and GETVXRES() macros to take a pointer to the fbcon_display struct. This fixes the build when console rotation is enabled and helps the compiler again to optimize out code. Signed-off-by: Helge Deller <deller@gmx.de> Cc: stable@vger.kernel.org # v5.10+ Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: https://patchwork.freedesktop.org/patch/msgid/20220202135531.92183-4-deller@gmx.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.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.