From: Knut Petersen updatescrollmode() must not select ywrap scrolling if divides(vc->vc_font.height, yres) is not true as this is not supported by the actual ywrap scrolling code. The bug is triggered with e.g. mode 800x600, vxres 1024, vyres 8192, bpp 8, font dimensions 8x16, 8Mb video ram and FBINFO_HWACCEL_YWRAP set. If those conditions are met, scrolling is broken and garbage is permanently displayed at the bottom of the screen. No regression, no possible side effects. Definitely needed by cyblafb and probably needed by amifb. Signed-off-by: Knut Petersen Acked-by: Antonino Daplas Signed-off-by: Andrew Morton --- drivers/video/console/fbcon.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletion(-) diff -puN drivers/video/console/fbcon.c~fbcon-disable-ywrap-if-not-supported-by-fbcon-scrolling-code drivers/video/console/fbcon.c --- devel/drivers/video/console/fbcon.c~fbcon-disable-ywrap-if-not-supported-by-fbcon-scrolling-code 2005-12-13 14:01:02.000000000 -0800 +++ devel-akpm/drivers/video/console/fbcon.c 2005-12-13 14:01:02.000000000 -0800 @@ -1965,7 +1965,8 @@ static __inline__ void updatescrollmode( divides(ypan, vc->vc_font.height) && vyres > yres; int good_wrap = (cap & FBINFO_HWACCEL_YWRAP) && divides(ywrap, vc->vc_font.height) && - divides(vc->vc_font.height, vyres); + divides(vc->vc_font.height, vyres) && + divides(vc->vc_font.height, yres); int reading_fast = cap & FBINFO_READS_FAST; int fast_copyarea = (cap & FBINFO_HWACCEL_COPYAREA) && !(cap & FBINFO_HWACCEL_DISABLED); _