https://bugzilla.kernel.org/show_bug.cgi?id=75241 Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |benh@xxxxxxxxxxxxxxxxxxx --- Comment #30 from Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx> --- Your latest change broke it for me, sorry for the delay in noticing, that combination of machine & monitor was stuck in the dark ages for a while... The combo is Radeon R9 290 (from Sapphire) and good old Apple Cinema Display 23" (1920x1200x60 fixed resolution display) on DVI. I get a black screen with radeon. It works with Alex's amdgpu. The one liner that fixes it is in the PLL calculation: -ref_div_max = max(min(100 / post_div, ref_div_max), 1u); +ref_div_max = max(min(128 / post_div, ref_div_max), 1u); I noticed other differences though, the max fb div is 2047 with radeon and 4095 with amdgpu but the above is the key. This is a trace of amdgpu calculation (which works) after I sprinkled printk's around: [ 3.471131] fb_div_min/max=4/4095 pll_flags=400 [ 3.471132] by 10 ! fb_div_min/max=40/40950 [ 3.471133] ref_div_min=2 (from 0/2) [ 3.471133] ref_div_max=1023 (from 0/1023) [ 3.471134] vco_min/max=600000/1200000 [ 3.471134] post_div_min/max=4/7 [ 3.471135] initial nom=153970, den=2700 [ 3.471136] reduced nom=15397, den=270 [ 3.471136] - trying post_div 4, ref_div_max=32 [ 3.471137] tentative ref_div=32m, fb_div=7299 [ 3.471137] adjusted ref_div=32m, fb_div=7299 [ 3.471138] diff=7, diff_best=-1 [ 3.471138] - trying post_div 5, ref_div_max=25 [ 3.471139] tentative ref_div=25m, fb_div=7128 [ 3.471139] adjusted ref_div=25m, fb_div=7128 [ 3.471139] diff=6, diff_best=7 [ 3.471140] - trying post_div 6, ref_div_max=21 [ 3.471140] tentative ref_div=21m, fb_div=7185 [ 3.471141] adjusted ref_div=21m, fb_div=7185 [ 3.471141] diff=6, diff_best=6 [ 3.471141] - trying post_div 7, ref_div_max=18 [ 3.471142] tentative ref_div=18m, fb_div=7185 [ 3.471142] adjusted ref_div=18m, fb_div=7185 [ 3.471150] diff=6, diff_best=6 [ 3.471150] post_div_best=7 [ 3.471151] - trying post_div 7, ref_div_max=18 [ 3.471151] tentative ref_div=18m, fb_div=7185 [ 3.471152] adjusted ref_div=18m, fb_div=7185 [ 3.471153] [drm:amdgpu_pll_compute] 153970 - 153960, pll dividers - fb: 239.5 ref: 6, post 7 Now this is with radeon *NOTE: I have bumped the max fb div to the same as AMD GPU when taking that trace but that had no effect: [ 4.718126] fb_div_min/max=4/4095 pll_flags=410 [ 4.718126] by 10 ! fb_div_min/max=40/40950 [ 4.718127] ref_div_min=2 (from 0/2) [ 4.718128] ref_div_max=1023 (from 0/1023) [ 4.718128] vco_min/max=600000/1200000 [ 4.718129] post_div_min/max=4/7 [ 4.718129] initial nom=153970, den=2700 [ 4.718130] reduced nom=15397, den=270 [ 4.718130] - trying post_div 4, ref_div_max=25 [ 4.718131] tentative ref_div=25m, fb_div=5703 [ 4.718131] adjusted ref_div=25m, fb_div=5703 [ 4.718132] diff=11, diff_best=-1 [ 4.718133] - trying post_div 5, ref_div_max=20 [ 4.718133] tentative ref_div=20m, fb_div=5703 [ 4.718133] adjusted ref_div=20m, fb_div=5703 [ 4.718134] diff=11, diff_best=11 [ 4.718134] - trying post_div 6, ref_div_max=16 [ 4.718135] tentative ref_div=16m, fb_div=5474 [ 4.718135] adjusted ref_div=16m, fb_div=5474 [ 4.718136] diff=14, diff_best=11 [ 4.718136] - trying post_div 7, ref_div_max=14 [ 4.718136] tentative ref_div=14m, fb_div=5589 [ 4.718137] adjusted ref_div=14m, fb_div=5589 [ 4.718137] diff=12, diff_best=11 [ 4.718138] post_div_best=5 [ 4.718138] - trying post_div 5, ref_div_max=20 [ 4.718139] tentative ref_div=20m, fb_div=5703 [ 4.718139] adjusted ref_div=20m, fb_div=5703 [ 4.718141] [drm:radeon_compute_pll_avivo] 153970 - 153980, pll dividers - fb: 570.3 ref: 20, post 5 The modeline is: Modeline 55:"1920x1200" 60 153970 1920 1968 2000 2080 1200 1203 1209 1235 0x48 0x9 And is consistent between the 2 drivers. -- You are receiving this mail because: You are watching the assignee of the bug. _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
