tree 7a5c97cdcbf0bf6a56a05839ee233a250d4c9eea
parent 3f08ff4a4dab1ebef06d154050fb80ce2c13fc9c
author Knut Petersen <Knut_Petersen@t-online.de> 1136868816 -0800
committer Linus Torvalds <torvalds@g5.osdl.org> 1136908910 -0800

[PATCH] fbcon: disable ywrap if not supported by fbcon scrolling code

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 <Knut_Petersen@t-online.de>
Acked-by: Antonino Daplas <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>