On Tue, 19 May 2020 17:10:41 -0600 Simon Glass s...@chromium.org wrote: > Some architectures use a cached framebuffer and flush the cache as needed > so that changes are visible. This is supported by U-Boot. > > However x86 uses an uncached framebuffer with a 'write-combining' feature > to speed up writes. Reads are permitted but they are extremely expensive. > > Unfortunately, reading from the frame buffer is quite common, e.g. to > scroll it. This makes scrolling very slow. > > Add a new feature which supports copying modified parts of the frame > buffer to the uncached hardware buffer. This speeds up scrolling by at > least 10x on x86 so the extra complexity cost seems worth it. > > As a starting point, add the Kconfig, update the video structures to keep > track of the buffer and add a function to do the copy. > > Signed-off-by: Simon Glass <s...@chromium.org>
Reviewed-by: Anatolij Gustschin <ag...@denx.de>
