tree aaedfb3128a400d8953e86e359763606a16a9fc2
parent 54541a75bfb6fd9659c1321a490554f4cb99b286
author Peter Rosin <peda@axentia.se> 1545329587 +0100
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> 1549997235 +0100

fbdev: fbmem: behave better with small rotated displays and many CPUs

[ Upstream commit f75df8d4b4fabfad7e3cba2debfad12741c6fde7 ]

Blitting an image with "negative" offsets is not working since there
is no clipping. It hopefully just crashes. For the bootup logo, there
is protection so that blitting does not happen as the image is drawn
further and further to the right (ROTATE_UR) or further and further
down (ROTATE_CW). There is however no protection when drawing in the
opposite directions (ROTATE_UD and ROTATE_CCW).

Add back this protection.

The regression is 20-odd years old but the mindless warning-killing
mentality displayed in commit 34bdb666f4b2 ("fbdev: fbmem: remove
positive test on unsigned values") is also to blame, methinks.

Fixes: 448d479747b8 ("fbdev: fb_do_show_logo() updates")
Signed-off-by: Peter Rosin <peda@axentia.se>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Fabian Frederick <ffrederick@users.sourceforge.net>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
cc: Geoff Levand <geoff@infradead.org>
Cc: James Simmons <jsimmons@users.sf.net>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>