Re: funny framebuffer fonts on PowerBook with radeonfb

[Herbert Poetzl]

On Mon, Mar 27, 2006 at 09:19:55AM +0800, Antonino A. Daplas wrote:
> Herbert Poetzl wrote:
> > Hey Ben!
> > 
> > 2.6.16 and 2.6.15-something show a funny behaviour
> > when using the radeonfb driver (for text mode), they
> > kind of twist and break the fonts in various places
> > some characters or parts seem to be mirrored like
> > '[' becoming ']' but not on character boundary but
> > more on N pixels, colors seem to be correct for the
> > characters, and sometimes the font is perfectly fine
> > for larger runs, e.g. I can read the logon prompt
> > fine, but everything I type is garbled ...
> > 
> > just for an example, when I type 'echo "Test"' then
> > all characters are mirrored and cut off on the right
> > side but the locations are as shown above, on enter
> > the T is only a few pixels wide, but the est part is
> > written perfectly fine ... this is a new behaviour
> > and going back to 2.6.13.3 doesn't show this ...
> > 
> > if there is some testing I can do for you, or when
> > you need more info, please let me know. here a few
> > details for the machine:
> > 
> 
> What font are you using? I presume the dimensions are
> not divisible by 8.  

precisely!

> Can you try this patch?

yes, I did, and I can confirm this one fixes it for me
thanks a lot for the fast response and the quite
accurate fix!

best,
Herbert

it's obvious, but if you can make use of that:

Acked-by: Herbert Poetzl <herbert@xxxxxxxxxxxx>

> Tony
> 
> diff --git a/drivers/video/cfbimgblt.c b/drivers/video/cfbimgblt.c
> index 910e233..8ba6152 100644
> --- a/drivers/video/cfbimgblt.c
> +++ b/drivers/video/cfbimgblt.c
> @@ -169,7 +169,7 @@ static inline void slow_imageblit(const 
>  
>  		while (j--) {
>  			l--;
> -			color = (*s & 1 << (FB_BIT_NR(l))) ? fgcolor : bgcolor;
> +			color = (*s & (1 << l)) ? fgcolor : bgcolor;
>  			val |= FB_SHIFT_HIGH(color, shift);
>  			
>  			/* Did the bitshift spill bits to the next long? */
> diff --git a/include/linux/fb.h b/include/linux/fb.h
> index 17fc771..4fe1d2d 100644
> --- a/include/linux/fb.h
> +++ b/include/linux/fb.h
> @@ -841,12 +841,10 @@ struct fb_info {
>  #define FB_LEFT_POS(bpp)          (32 - bpp)
>  #define FB_SHIFT_HIGH(val, bits)  ((val) >> (bits))
>  #define FB_SHIFT_LOW(val, bits)   ((val) << (bits))
> -#define FB_BIT_NR(b)              (7 - (b))
>  #else
>  #define FB_LEFT_POS(bpp)          (0)
>  #define FB_SHIFT_HIGH(val, bits)  ((val) << (bits))
>  #define FB_SHIFT_LOW(val, bits)   ((val) >> (bits))
> -#define FB_BIT_NR(b)              (b)
>  #endif
>  
>      /*
> -
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