If you ever been wondered why your GNU/Linux Debian missing the DRI capability, you should know that now Debian ships the Firmware into new package called:

firmware-linux

This is due to legal and political policy of Debian which is not wanting to be tainted by non-free softwares. The package is containing BLOB [non-techie reader reads: no source, binary only) firmwares that needed to activated some of the capability. I guess that is the price of freedom and good quality means.