[Linux-fbdev-devel] Re: Console rotation problems

[Antonino A. D. <ad...@gm...>]

Benjamin Herrenschmidt wrote:
> Remove bogus usage of test/set_bit() from fbcon rotation code and just
> manipulate the bits directly. This fixes an oops on powerpc among others
> and should be faster. Seems to work fine on the G5 here.

Thanks, I reached a point when my head became muddled with bit 
manipulations, so I used arch-specific bitops but complete forgot
that they were atomic :-)

> 
> Signed-off-by: Benjamin Herrenschmidt <be...@ke...>
Acked-by: Antonino Daplas <ad...@po...>

> ---
> 
> And here is the fix. Tony, did I miss something ?

Works in little-endian too, so thank you very much. cfbimageblit may
also suffer from this same mistake (mine).  So can you test with
12x22 fonts at rotate 1 or 3 with acceleration off?

This particular line in cfbimgblit.c:slow_imageblit() is definitely
questionable.

- color = (*s & 1 << (BIT_NR(l))) ? fgcolor : bgcolor;
+ color = (*s & (1 << l)) ? fgcolor : bgcolor;


Tony