Try switching to that kernel.
]]>(As an observation, KMS doesn't seem to be active since the resolution doesn't change during booting, which it used to do.)
I have a Radeon HD 6770.
Downgrading to 6.14 didn't help at all: KMS was apparently disabled, KDE started, but with both displays in clone mode (which couldn't be changed), and X crashed when changing to tty and back to X.
There are a couple of threads reporting problems with the update, but I don't get a segfault, just the error message "no screens found".
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