https://bugzilla.kernel.org/show_bug.cgi?id=24462
--- Comment #5 from Alex Deucher alexdeucher@gmail.com 2010-12-08 21:14:47 --- Created an attachment (id=39362) --> (https://bugzilla.kernel.org/attachment.cgi?id=39362) possible fix
(In reply to comment #2)
but 2.6.36 uses ENABLE_SPREAD_SPECTRUM_ON_PPLL_PS_ALLOCATION, while the newer kernel uses ENABLE_LVDS_SS_PARAMETERS_V2 for the parameters (the only difference is that the latter does not have ucPpll); is this correct?
That is correct. I suspect it's the pll that's problematic: if (ss_enabled) { if (ss->refdiv) { pll->flags |= RADEON_PLL_USE_REF_DIV; pll->reference_div = ss->refdiv; } }
It uses a fixed reference divider of 2 in your case. Does the attached patch help? Please also try this patch in conjunction with the patch in comment 1.