Control fb problem on 8500

Hello,

A couple of issues have cropped up with my PowerMac 8500.  I am running
Paulus' 2.4.0-test6 kernel and my console has developed a sort of mirror
image on the far right one-eighth of the screen.  Basically, everything on
the screen is mirrored in that eighth of the screen albeit much
smaller.  For example, as I type this, tiny white lines are being drawn to
my right.  If I were to `ls --color` a directory, different color lines
show up.  This behaviour wasn't there in Paulus' 2.4.0-test1-ac21 kernel
of a few rsyncs ago.

Secondly, the video chip doesn't show up on the PCI bus.  Although XFree86
4.0 apparently supports the controlfb (which is what the 8500 has), it
also needs a BusID to be used.  Am I out of luck with using XFree86 4.0 or
newer with my machine?  Or generically, is anyone without a card on the
PCI bus out of luck?

Thanks,

Kevin

--
Kevin M. Myer
Systems Administrator
Lancaster-Lebanon Intermediate Unit 13
(717)-560-6140


** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/

"Kevin M. Myer" wrote:

Secondly, the video chip doesn't show up on the PCI bus.  Although XFree86
4.0 apparently supports the controlfb (which is what the 8500 has), it
also needs a BusID to be used.  Am I out of luck with using XFree86 4.0 or
newer with my machine?  Or generically, is anyone without a card on the
PCI bus out of luck?

No, the contrary, you're very lucky! :)

As the chip doesn't show up, the X server can't deactivate it. So you don't
need to specify a bus ID (which would prevent the server of disabling the chip ;).


Michel

** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/

Hi there,

On  15 Aug, this message from Kevin M. Myer echoed through cyberspace:

A couple of issues have cropped up with my PowerMac 8500.  I am running
Paulus' 2.4.0-test6 kernel and my console has developed a sort of mirror
image on the far right one-eighth of the screen.  Basically, everything on
the screen is mirrored in that eighth of the screen albeit much
smaller.  For example, as I type this, tiny white lines are being drawn to
my right.  If I were to `ls --color` a directory, different color lines
show up.  This behaviour wasn't there in Paulus' 2.4.0-test1-ac21 kernel
of a few rsyncs ago.

I've seen this too; but have no explanation. It might be caused by
hardware running on the limit of it's spec; control is quite picky in
this respect. But then again, something changed that made the problems
apear...

Secondly, the video chip doesn't show up on the PCI bus.  Although XFree86
4.0 apparently supports the controlfb (which is what the 8500 has), it
also needs a BusID to be used.  Am I out of luck with using XFree86 4.0 or
newer with my machine?  Or generically, is anyone without a card on the
PCI bus out of luck?

Since control has its own dedicated PCI-like bus (Apple calls it a
'VCI'), it will not show up as a PCI device unless you use a PCI-patched
kernel. The missing BusID is not a problem for XF4, rest assured.
However, XF4 does not support control directly, but rather through the
generic framebuffer driver.

See my page:

http://www.cpu.lu/~mlan/linux/dev/xf4.html

on how to get XF4 to work with control.

Michel

-------------------------------------------------------------------------
Michel Lanners                 |  " Read Philosophy.  Study Art.
23, Rue Paul Henkes            |    Ask Questions.  Make Mistakes.
L-1710 Luxembourg              |
email   mlan@cpu.lu            |
http://www.cpu.lu/~mlan        |                     Learn Always. "


** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/

Hi there,

On  15 Aug, this message from Kevin M. Myer echoed through cyberspace:

A couple of issues have cropped up with my PowerMac 8500.  I am running
Paulus' 2.4.0-test6 kernel and my console has developed a sort of mirror
image on the far right one-eighth of the screen.  Basically, everything on
the screen is mirrored in that eighth of the screen albeit much
smaller.  For example, as I type this, tiny white lines are being drawn to
my right.  If I were to `ls --color` a directory, different color lines
show up.  This behaviour wasn't there in Paulus' 2.4.0-test1-ac21 kernel
of a few rsyncs ago.

I was able to boot a 2.4.0-t6 kernel tonight (it's like once in a
million boots for me right now with 2.4.0) and experienced the same
problem; although I had only like 6-8 pairs of single-pixel horizontal
lines, maybe 150 or so pixels long, on the right edge of the screen.

Those lines mirrored image content from the left side of the screen, at
the same height, and around 150 pixels inside the screen. I could also
verify that those 'lines' are not part of the pixel data in VRAM, but
are only added on-screen by control.

I've also had a look at what changed on control from earlier versions,
and found only the pitch of the lines that changed.

In fact, before, the line length was exactly hpixels * bytes/pixel,
whereas now there's an additional 0x20 bytes in each line. I have not
been able to boot a 2.4.0 kernel with any fix applied, but you could try
and build a version without those 0x20 bytes added (they are found in a
few spots inside controlfb.c).

As to why these 0x20 bytes were added, anybody know an explanation? And,
if they do serve a purpose (I suppose so ;-), it would be better to add
the exact number of bytes as a #define somewhere...

Thanks

Michel

-------------------------------------------------------------------------
Michel Lanners                 |  " Read Philosophy.  Study Art.
23, Rue Paul Henkes            |    Ask Questions.  Make Mistakes.
L-1710 Luxembourg              |
email   mlan@cpu.lu            |
http://www.cpu.lu/~mlan        |                     Learn Always. "


** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/