Xorg freezes at startup when video card uses AGP 8x

[Danilo Piazzalunga]

On my system[1] I have an ATI Radeon 9200SE video card, which can operate in AGP modes 4x and 8x. If the BIOS settings specify AGP 8x (the default setting) and Xorg's ati driver (with dri enabled) tries to use AGP 4x (or whatever), Xorg freezes and the result is an unusable system (no video output and no response from keyboard input; but the system still responds remotely, most of the time).

Setting either Option "AGPMode" "8" in xorg.conf or AGP 4x in the BIOS makes Xorg start up and work fine. Note that if the BIOS specifies AGP 4x and xorg.conf sets AGPMode 8, there are some complains from the kernel agpgart module but everything works.

[1] http://hwdb.ubuntu.com/?xml=18dcdf861a5b1ca8f4a9103176ccc0f1

[Danilo Piazzalunga (danilopiazza)]

These are the syslog snippets of what happens in all the cases I have tested.

1. BIOS: AGP 8x

1.1. Xorg: AGP 4x or less (default)

[4315054.408000] [drm] Initialized drm 1.0.0 20040925
[4315054.420000] ACPI: PCI Interrupt 0000:01:00.0[A] -> GSI 16 (level, low) -> IRQ 201
[4315054.421000] [drm] Initialized radeon 1.19.0 20050911 on minor 0:
[4315054.422000] agpgart: Found an AGP 3.5 compliant device at 0000:00:00.0.
[4315054.422000] agpgart: Badness. Don't know which AGP mode to set. [bridge_agpstat:1f000a0a vga_agpstat:ff00021b fell back to:- bridge_agpstat:1f000208 vga_agpstat:ff00021b]
[4315054.422000] agpgart: Bridge couldn't do AGP x4.
[4315054.422000] agpgart: Putting AGP V3 device at 0000:00:00.0 into 0x mode
[4315054.422000] agpgart: Putting AGP V3 device at 0000:01:00.0 into 0x mode
[4315054.430000] [drm] Loading R200 Microcode

* Result: Xorg freezes, system unusable.

1.2. Xorg: AGP 8x

[4294726.584000] [drm] Initialized drm 1.0.0 20040925
[4294726.600000] ACPI: PCI Interrupt 0000:01:00.0[A] -> GSI 16 (level, low) -> IRQ 201
[4294726.601000] [drm] Initialized radeon 1.19.0 20050911 on minor 0:
[4294726.602000] agpgart: Found an AGP 3.5 compliant device at 0000:00:00.0.
[4294726.602000] agpgart: Xorg tried to set rate=x12. Setting to AGP3 x8 mode.
[4294726.602000] agpgart: Putting AGP V3 device at 0000:00:00.0 into 8x mode
[4294726.602000] agpgart: Putting AGP V3 device at 0000:01:00.0 into 8x mode
[4294726.710000] [drm] Loading R200 Microcode

2. BIOS: AGP 4x

2.1. Xorg: AGP 4x or less (default)

[4294785.033000] ACPI: PCI Interrupt 0000:01:00.0[A] -> GSI 16 (level, low) -> IRQ 201
[4294785.034000] [drm] Initialized radeon 1.19.0 20050911 on minor 0:
[4294785.035000] agpgart: Found an AGP 3.5 compliant device at 0000:00:00.0.
[4294785.035000] agpgart: Putting AGP V3 device at 0000:00:00.0 into 4x mode
[4294785.035000] agpgart: Putting AGP V3 device at 0000:01:00.0 into 4x mode
[4294785.109000] [drm] Loading R200 Microcode

2.2. Xorg: AGP 8x

[4298768.352000] agpgart: Found an AGP 3.5 compliant device at 0000:00:00.0.
[4298768.352000] agpgart: Xorg tried to set rate=x12. Setting to AGP3 x8 mode.
[4298768.352000] agpgart: Xorg requested AGPx8 but bridge not capable.
[4298768.352000] agpgart: Putting AGP V3 device at 0000:00:00.0 into 4x mode
[4298768.352000] agpgart: Putting AGP V3 device at 0000:01:00.0 into 4x mode
[4298768.360000] [drm] Loading R200 Microcode

[Danilo Piazzalunga (danilopiazza)]

The above comment garbled the log formatting. Reposting as an attachment.

[Herbert Straub (herbert)]

I had the same problem on my computer since Brezzy Colony 2 and i wrote a comment in bugzilla #6188 (https://bugzilla.ubuntu.com/show_bug.cgi?id=6188). Today i installed Dapper Flight 5 with the same problem (my workaround was commenting out load dri).

Now i changed the BIOS setup to AGB 4x and X works fine. I noticed the same situation with Fedora Core 5 test3(?).