Re: [Linux-fbdev-devel] accelerated radeonfb produces artifacts on scrolling in 2.6.7

[Timothy M. <mi...@te...>]

David Eger wrote:
> On Wed, Jun 16, 2004 at 08:24:15PM +0200, Jurriaan wrote:
> 
>>The radeonfb driver in 2.6.7 produces some interesting artifacts on
>>scrolling, both scrolling horizontally and vertically.
> 
> 
> The corruption you are talking about is, I believe, caused by a couple of things:
> 
> (1) we're not issuing enough fifo_wait()'s around our accel engine
>     and pan register writes.
> (2) there's some disconnect between writing to fb memory, panning, and
>     copyarea()/fillrect() calls
> 
> I sent a hack of a fix for this to Ben a week ago, adding a call to radeonfb_sync()
> at the end of radeonfb_copyarea() and radeonfb_fillrect().  This seems to fix the
> problem for me, but you *shouldn't* have to do this.  
> 
> I haven't tracked it any further than this.  My next guess would be auditing register 
> writes and making sure there are enough fifo_wait()'s...


Is this the case even with the off-by-one error in the bitblt code 
fixed?  In the 2.4 kernel, I got rid of all artifacts by fixing the 
off-by-one error.

In case, you don't know what I'm talking about, when you bitblt up or to 
the left on Radeon, x and y need to be adjusted by (w-1) and/or (h-1), 
respectively.  The code there, however, adjusted by w and/or h, which is 
off-by-one.