Output Via DVI is Operational

Posted by Hans de Ruiter

Days after having my Amigaone back up and running the RadeonHD driver can now drive monitors via DVI.  Last night, a 1920x1080 @ 60 Hz screen was successfully opened by the driver (see the photo below).  This test was performed with an HIS Radeon X1550 PCI card (RV505 chipset). DVI, or Digital Visual Interface, is a monitor interfacing standard that uses digital signalling in order to achieve maximum quality. The older VGA standard used analog signals, which could degrade with long/poor cabling. 

1920x1080 @ 60 Hz output via DVI by the RadeonHD driver.

Bugs and the Graphics Card Quirk Table

The code for driving the DVI output was already in place, but untested. As it turns out, there were two hard to find issues that individually prevented the DVI from working. One was a simple bug (which was still hard to find); the other was a problem with the graphics card.

The biggest hurdle proved to be the HIS Radeon X1550 PCI graphics card. The AtomBIOS contains tables that inform the driver of the card's configuration. Unfortunately, a number of cards provide incorrect information, including the HIS Radeon X1550 PCI card. Thus, an entry into the quirk table had to be made. The quirk table is a table of workarounds for graphics cards that provide incorrect information. 

I have forwarded the quirk table entry to the open-source Linux RadeonHD driver team so that any Linux users that have this card will also be able to use the DVI output.

Comments (0) | 16 January 2009