Re: radeonfb and 16bit color problem

On Mon, Jun 24, 2002 at 05:24:11AM +0200, Benjamin Herrenschmidt wrote:

quoted

Any ideas would be helpful.  I tried looking at the code myself, but I'm
still quite new to the framebuffer code.  However, this part looked kind
of strange to me:

  /* For 565, the green component is mixed one order below */
  if (rinfo->depth == 16) {
     OUTREG(PALETTE_INDEX, pindex>>1);
     OUTREG(PALETTE_DATA, (rinfo->palette[regno>>1].red << 16) |
            (green << 8) | (rinfo->palette[regno>>1].blue));
     green = rinfo->palette[regno<<1].green;
  }


BTW, I have a Radeon 8500 (QL).

I wrote that part and it works just fine on my powerbook... at least
with the radeonfb version that is in my tree, but I don't think it
differs from the official one in this regard. You can try making sure
it's properly setting 32 palette entries for green when using that
mode.

I thought that piece of code looked weird because it's setting green
equal to rinfo->palette[regno<<1].green, but doesn't seem to ever use
green during the rest of the function...

BTW, don't you mean 64 palette entries for green (being that it's 6
bits)?  Anyways, I took some time this weekend to look over the code
some more, and I really doubt my problems originates in that function.
As I understand it, the palette (colormap?) will only be used when
displaying colors in text mode.

My problem seems to affect many more colors (practically all 65536 of
them), but I've yet to track it down.  I put in a request on ATI's
website to get access to the specs (hoping that'll help me), but I
haven't heard anything back from them yet.

Thanks,
Bryan

PS I'll try checking out your tree the next time I get a chance and see
if I still see the problem.


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I thought that piece of code looked weird because it's setting green
equal to rinfo->palette[regno<<1].green, but doesn't seem to ever use
green during the rest of the function...

It should about 2 lines below ... at least in my tree.

BTW, don't you mean 64 palette entries for green (being that it's 6
bits)? 

Yah, sorry, typing too fast ;)

Anyways, I took some time this weekend to look over the code
some more, and I really doubt my problems originates in that function.
As I understand it, the palette (colormap?) will only be used when
displaying colors in text mode.

Hrm... there HW colormap is used in all modes in recent drivers, thus
you can actually set a gamma table. The driver should set it to a
linear ramp by default though that may be broken.

My problem seems to affect many more colors (practically all 65536 of
them), but I've yet to track it down.  I put in a request on ATI's
website to get access to the specs (hoping that'll help me), but I
haven't heard anything back from them yet.

Ben.



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