Re: [PATCH 7/7] fbdev: Add Tile Blitting support

Petr Vandrovec
2004-09-10T00:13:42Z

On Fri, Sep 10, 2004 at 05:34:56AM +0800, Antonino A. Daplas wrote:
>
> In my case at least, the cleanup did produce an unexpected but beneficial
> side effect, a little more speedup. Not much, < 5%.
>
> Petr, if you have comments, suggestions, or you think this is a bad idea,
> let me know.

It looks like good idea to me. Though I still do not see benefits
2.6.x fbcon provides over 2.4.x.

BTW, there is still bad bug with software scrollback and multihead
(it is here since I remember): redraw_screen sets redraw to 0 when
old_console == new_console, but fbcon uses con_switch() method for
deciding whether software scrollback should be reinitialized or not.
As software scrollback is per-system and not per-fbdev thing, this
has rather nasty consequences - when both fbdevs have different xres,
console user can crash system (con2fb /dev/fb1 /dev/tty11; set xres
fb0 != xres fb1; chvt 11; chvt 10; chvt 11; hit alt-shift-pgup
or force vt11 to scroll; crash, some kernel data structures were
overwritten with 0x0720...).
Petr Vandrovec