AMD's "Mystery" Digital Block Supported

[phoronix]

Phoronix: AMD's "Mystery" Digital Block Supported

For those using motherboards with the AMD RS690 IGP, the DDIA Digital Block is now supported by the RadeonHD (xf86-video-radeonhd) driver. DDIA is the second digital block on this IGP that came as a mystery to both AMD and the RadeonHD developers as they believed no motherboard vendors were actually using this block...

http://www.phoronix.com/vr.php?view=NjQwNg

[BlueKoala]

AMD's devices are so feature rich that they discover devices they weren't aware they had? :P

[bridgman]

Something like that ;)

Seriously, the IGP parts have a huge number of configuration options. At the start of the project we put together a list of blocks and identified which ones were highest priority for documentation and support. Initial feedback was that none of the mobo vendors were using this particular block, so we put it near the bottom of the list and focused on documenting the bits we knew *were* being used.

It turned out that the block was being used after all, primarily for HDMI out.

[Thetargos]

How can I know if the one on my laptop has this mystery block?

[BlueKoala]

How can I know if the one on my laptop has this mystery block?

I would suspect it would if you have HDMI out or dual video out on a RS690M chipset. With an Intel CPU I believe it would be the RS690M chipset. In any case, it is better known as the Radeon Xpress 1200 series.

If you have dual monitor or HDMI output that didn't/doesn't work, I supposed you can expect it to magically start working in the not so distant future after a driver update.

=]

[Thetargos]

Indeed, I have an X1200 (eXpress 1200) and I do have dual video out (VGA and S-VIDEO) on the side, so I guess I do have this "mystery" block.

[BlueKoala]

I'm not sure if s-video would be it though. You can always test it see if it works though!

[bridgman]

There are two ways to tell :

1. Pick through your BIOS contents

2. If one of your digital outputs (typically HDMI) doesn't work, try the new driver and see if it starts working.

There may be a log message from the driver when it sets up the block, but of course the message wouldn't happen unless you put the latest driver from git on your system so you're back to (2).

[agd5f]

Indeed, I have an X1200 (eXpress 1200) and I do have dual video out (VGA and S-VIDEO) on the side, so I guess I do have this "mystery" block.

The DDIA block is for digital outputs only (i.e, HDMI). VGA and TV are handled by the DAC. You'll probably have DDIA if you have a board with independent DVI and HDMI ports.

[DanL]

The DDIA block is for digital outputs only (i.e, HDMI). VGA and TV are handled by the DAC. You'll probably have DDIA if you have a board with independent DVI and HDMI ports.

So this doesn't help with the DVI scanline bug in any way if you already have DVI working? Sigh, I guess I have to report this bug (I was hoping it would be fixed by now) :(

BTW, for those of you confused: Radeon X1200 = no HDMI, X1250 = HDMI

[DanL]

So this doesn't help with the DVI scanline bug in any way if you already have DVI working?

Wow! It actually fixed it. All hail the Magical Mystery Block.

[BlueKoala]

Hail to the mystery block!

[bridgman]

The issue here as I understand it is that the initial POST setup was pretty close and worked for many users, but adding the driver support (a) fixed some remaining issues, and (b) allowed the output to work even if a display was not connected at power-up (the POST only initializes connected outputs).