https://bugs.freedesktop.org/show_bug.cgi?id=87682
--- Comment #14 from Thom madeforspam@telfort.nl --- (In reply to Chris Bainbridge from comment #13)
This might be https://bugzilla.kernel.org/show_bug.cgi?id=75241 - there is one line patch there from Christian König but it doesn't look like it was ever merged.
I did a git fetch origin , git reset --hard origin/master to get a plain unaltered current kernel again (4.6.0-rc7+)
I changed the one line in ./drivers/gpu/drm/radeon/radeon_display.c: fb_div_max = pll->max_feedback_div; to: fb_div_max = min(pll->max_feedback_div, 512u); according to: https://bugzilla.kernel.org/attachment.cgi?id=142281 (linked from https://bugzilla.kernel.org/show_bug.cgi?id=75241)
and compiled (make && make modules_install install)
Assuming that i did not make a mistake or overlooked something; this patch didn't work, lots of noise/artefacts. Timings seem identical to the other "bad" compilations, i.e. nothing changed:
(bootparam drm.debug=4) [drm:radeon_compute_pll_avivo] 69300 - 69290, pll dividers - fb: 135.5 ref: 2, post 14
too bad, but it was absolutely worth to try. I wonder if "fb" and "post" are consequently too low....is that possible ?