Table of Contents
To control a monitor, DDCcontrol must access to the I2C bus of the graphics card. There are two methods to do so: the first one uses /dev/i2c-* devices provided by kernel drivers (abbreviated by dev in tables), the second one reads and writes directly in the card PCI memory (abbreviated by PCI in the tables).
Depending on your hardware, one method or the other works, or even both.
Almost every ATI cards should work with direct PCI memory access, even if it has not been very extensively tested.
To use it, you have nothing special to do, everything is done by DDCcontrol.
ATI Radeon cards also work with /dev/i2c-* devices. To use /dev/i2c-* devices with ATI cards, you must load the radeonfb module by typing, as root:
# modprobe radeonfb
The kernel configuration options needed to enable Radeon framebuffer driver and I2C support are:
The radeonfb kernel module may cause system instability (crashes or screen corruption) when used at the same time as used the ATI closed source drivers.
This is why we recommend that you use direct PCI memory access with ATI cards.
These ATI cards have been reported to work, but others models should also work. If yours is not listed, please send a message to one of the DDCcontrol mailing lists (see Appendix A, Report problems and successes).
| Name | Works | |
|---|---|---|
| dev | PCI | |
| Radeon 7000 | Yes | ??? |
| Radeon 7500 | Yes | ??? |
| Radeon 9200 | Yes | ??? |
| Radeon 9500 | Yes | ??? |
| Radeon 9550 SE | Yes | ??? |
| Radeon 9600 Pro | Yes | ??? |
| Radeon 9700 | Yes | ??? |
| Radeon 9800 Pro | Yes | Yes |