(In reply to samdenies from comment #102)
> I want to add another data point for a card not yet mentioned in this bug. 
> I have had this issue for quite some time, awaiting a fix.  I run a
> fully-updated Debian testing, and my card is described below.
> 
> XFX R9 270X
> Vendor ID: 1002
> Device ID: 6810
> Subsystem Vendor ID: 1682
> Subsystem Device ID: 9275
> 
> I don't believe this matches the existing quirk, and I haven't created a
> custom kernel to add one.  Running with radeon.drm=0 allows it to boot and
> basically function, but with very poor 3D performance.
> 
> I'd be more than happy to provide any additional diagnostic information
> within my abilities to collect, and test any potential fixes.

Please attach the output of lspci -vnn