X problems with CT65555 video hardware

I'm testing a 4.6 snapshot dated 07/09/2009 on my
old Toshiba laptop that has a Chips and Technologies
CT65555 video subsystem.

Running X -configure creates an xorg.conf.new file that
calls for the correct driver ("chips"), but the result
of using this file in X -config /root/xorg.conf/new
is not usable video. I had thought that experimenting
with the contents of xorg.conf.new would eventually
lead to a solution, but so far I've been unsuccessful.

When I look at the log file the first problem I find
is the driver thinks there's only 256K of video ram:

(--) CHIPS(0): VideoRAM: 256 kByte

It should have found 2048K. I added a "VideoRam 2048"
line to the the config file to override the probed
value and that results in different but still quite
useless video.

I'm guessing that some other people (at least a few)
are testing the chips driver with 4.6 successfully
elsewhere, and so this problem could be unique to my
old Toshiba 330CDT laptop. Perhaps I have a buggy
bios. I do not think I have defective hardware as
X/chips still works fine with OpenBSD 4.4 installed.

Comparing the dmesg outputs from 4.4 and 4.6 shows
only one significantly different section:

4.4-release dmesg output contains these lines:

pci0 at mainbus0 bus 0: configuration mode 1 (no bios)
pchb0 at pci0 dev 0 function 0 "Toshiba PCI" rev 0xa0
vga1 at pci0 dev 4 function 0 "Chips and Technologies 65555" rev 0xc6
wsdisplay0 at vga1 mux 1: console (80x25, vt100 emulation)
wsdisplay0: screen 1-5 added (80x25, vt100 emulation)
drm at vga1 unsupported

4.6-current (07/09/2009) dmesg contains these lines:

pci0 at mainbus0 bus 0: configuration mode 1 (bios)
pchb0 at pci0 dev 0 function 0 "Toshiba PCI" rev 0xa0
vga1 at pci0 dev 4 function 0 "Chips and Technologies 65555" rev 0xc6
wsdisplay0 at vga1 mux 1: console (80x25, vt100 emulation)
wsdisplay0: screen 1-5 added (80x25, vt100 emulation)


I also captured and compared the outputs from pcidump
under both 4.4 and 4.6 by doing fresh installs and
running "pcidump", "pcidump -v", "pcidump -x", and
"pcidump -xx".

Running pcidump from 4.6 (07/09/2009) yields:

Domain /dev/pci0:
 0:0:0: Toshiba PCI
 0:4:0: Chips and Technologies 65555
 0:11:0: NEC USB
 0:17:0: Toshiba Fast Infrared Type O

There's no significant difference between the outputs
with -v and -x options, but -xx produces a difference
only in the first section. (I don't know if this is
significant or not.)

4.4-release pcidump -xx 0:0:0 output is shown below:

0:0:0: Toshiba PCI
	0x0000: 06011179 22800006 060000a0 00000008
	0x0010: 00000000 00000000 00000000 00000000
	0x0020: 00000000 00000000 00000000 00011179
	0x0030: 00000000 00000000 00000000 00000000
	0x0040: 00001500 000002bf dfc41819 00000003
	0x0050: 00000018 00000000 fd000007 fdf00000
	0x0060: 00000000 00000000 001a01f0 00000000
	0x0070: 00000000 00000000 00000000 00000000
	0x0080: 0ffc0133 00000000 0d480000 00000003
	0x0090: 000248ff 0000000b 00000000 00000000
	0x00a0: 0000001a 000000c2 0000001f 4000ffff
	0x00b0: 00000000 00000000 00000000 00000000
	0x00c0: 00000000 00000000 00000026 00000018
	0x00d0: 00000000 0cf40000 00006a9c 00000000
	0x00e0: 00000000 00000000 00000000 00000000
	0x00f0: 00000000 00000000 00000000 00000008

4.6-current (07/09/2009) pcidump -xx 0:0:0 output is:

Domain /dev/pci:
 0:0:0: Toshiba PCI
	0x0000: 06011179 22800006 060000a0 00000008
	0x0010: 00000000 00000000 00000000 00000000
	0x0020: 00000000 00000000 00000000 00011179
	0x0030: 00000000 00000000 00000000 00000000
	0x0040: 00001500 000002bf dfc41819 00000003
	0x0050: 00000018 00000000 fd000007 fdf00000
	0x0060: 00000000 00000000 001a01f0 00000000
	0x0070: 00000000 00000000 00000000 00000000
	0x0080: 0ffc0133 00000000 0d040000 00000003
	0x0090: 000248ff 0000000b 00000000 00000000
	0x00a0: 0000001a 000000c2 0000001f 4000ffff
	0x00b0: 00000000 00000000 00000000 00000000
	0x00c0: 00000000 00000000 00000026 00000018
	0x00d0: 00000000 1eec0000 000023a4 00000000
	0x00e0: 00000000 00000000 00000000 00000000
	0x00f0: 00000000 00000000 00000000 00000008

diff -w between these two output files yields:

0a1
> Domain /dev/pci:
10c11
< 	0x0080: 0ffc0133 00000000 0d480000 00000003
---
> 	0x0080: 0ffc0133 00000000 0d040000 00000003
15c16
< 	0x00d0: 00000000 0cf40000 00006a9c 00000000
---
> 	0x00d0: 00000000 1eec0000 000023a4 00000000


So here is my question. Is is possible that my X
troubles are related to the above differences in
the way PCI space looks between the 4.4 and 4.6?

Thanks for any thoughts on this.

Mike Beasley