libpayload: cbgfx: Clear screen by sequential access

Currently clear_screen() calls set_pixel() to set all pixels. However,
the actual order of pixels being set depends on the framebuffer
orientation. With NORMAL orientation, the framebuffer is accessed
sequentially; with LEFT_UP/RIGHT_UP orientation, it is accessed back and
forth, leading to performance drop (>1 second on bugzzy).

Therefore, ensure sequential access to the framebuffer, regardless of
the orientation.

BUG=b:194967458
TEST=emerge-cherry libpayload
BRANCH=dedede

Change-Id: Iecaff5b6abc24ba4b3859cbc44c0d61b2a90b2d9
Signed-off-by: Yu-Ping Wu <yupingso@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/57104
Reviewed-by: Hung-Te Lin <hungte@chromium.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

0 files changed, 0 insertions, 0 deletions