All mentioned computers run Fedora 14 x86_64 with KMS. On my work machine with an Intel graphics chipset and a flat panel with working EDID, vanilla kernels 2.6.37-rc6 and 2.6.37-rc5 works OK. On my home machine, with a somewhat different Intel graphics chipset, and a flat panel that does *not* report EDID information, 2.6.37-rc5 works OK but 2.6.37-rc6 blanks the KMS display on boot. I get the "no signal" message on the panel instead of a working display. I was able to bisect this to the following commit: commit 541cc966915b6756e54c20eebe60ae957afdb537 Author: Chris Wilson <chris@chris-wilson.co.uk> Date: Mon Dec 6 11:24:07 2010 +0000 drm: Don't try and disable an encoder that was never enabled Prevents code that assumes that the encoder is active when asked to be disabled from dying a horrible death. Reported-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Signed-off-by: Dave Airlie <airlied@redhat.com> When I revert this commit, the problem goes away in my home machine.
Created attachment 41012 [details] lspci -vvvv on the affected machine.
Created attachment 41022 [details] Kernel configuration used to compile affected kernel
Created freedesktop.org bug https://bugs.freedesktop.org/show_bug.cgi?id=32527
*** This bug has been marked as a duplicate of bug 25242 ***