[t400/t500] Dock is broken

On the Lenovo T400 and T500, the Advanced Mini Dock hardly works. Only charging and VGA / DVI work, but USB and RS232 do nothing. I haven't tested ethernet yet, but it probably doesn't work either.

The eject button also doesn't work, nor does the LED indicator.

[ArthurHeymans]

T400 (T500/W500) code in coreboot is a simple clone of X200, including X200 dock code. Since the T400 is compatible with T60 dock (same dock?), it is probably possible to reuse a large part of that code (both SMI and ACPI). I suspect its a matter of setting right GPIOs and also setup SIO (which is trivial since T60 code is most certainly compatible).

Yes, same dock. X200 docks work mostly ok, but are completely different. Only the eject button on the X200 dock doesn't work for some reason, while Fn + F9 does.

After testing https://review.coreboot.org/#/c/18054/ I can conclude that:

(Mostly) working:

• USB now works in Linux, but not in GRUB;
• Both VGA and DVI work in Linux as a second screen, but LVDS is disabled in GRUB when VGA is connected (on the X200 the screens are mirrored);
• DVI does not work at all in GRUB, because of [ADD2/SDVO] No output in SeaBIOS / GRUB #13;
• Audio out works;
• Audio in works (shows up as dock microphone even);
• Ethernet works;
• Serial port + debugging works;
• The power button on the dock works;
• Suspend / resume when docked works.

Not working:

• The undock button on the dock and Fn + F9 do not work;
• The undock led indicators do not work;
• Undocking and then redocking results in a hard lockup.

ACPI: \_SB.DOCK: undocking
ACPI: \_SB.DOCK: No _EJ0 support for device

Untested:

• S-Video;
• Coaxial SPDIF;
• Parallel port;
• 56k modem.

[al12gamer]

Will this work with the T400 and Advanced Dock 2503 model?