Indeed, the two radeon parameters for PLL mention in previous message does not seems to appear anymore in modinfo radeon.
paul@paul-NC210-NC110:~/linux-stable$ git log --oneline v3.15-rc1..v3.15-rc2 | grep radeon bcddee29b0b8 drm/radeon/ci: make sure mc ucode is loaded before checking the size 8c79bae6a30f drm/radeon/si: make sure mc ucode is loaded before checking the size f8a2645ecede drm/radeon: improve PLL params if we don't match exactly v2 74073c9dd299 drm/radeon: memory leak on bo reservation failure. v2 681941c1790b drm/radeon: fix VCE fence command 7e1858f9aff7 drm/radeon: re-enable mclk dpm on R7 260X asics 277babc374f6 drm/radeon: add support for newer mc ucode on CI (v2) 1ebe92802eaf drm/radeon: add support for newer mc ucode on SI (v2) 5fb9cc4d8b16 drm/radeon: apply more strict limits for PLL params v2 6abc6d5c73b2 drm/radeon: update CI DPM powertune settings 90c4cde9d5a2 drm/radeon: fix runpm handling on APUs (v4) 57700ad1f2f2 drm/radeon: disable mclk dpm on R7 260X 8902e6f2b832 drm/radeon: Improve vramlimit module param documentation be0949f5eb9c drm/radeon: fix audio pin counts for DCE6+ (v2) 379dfc25e257 drm/radeon/dp: switch to the common i2c over aux code 25377b921b40 drm/radeon/dp: handle zero sized i2c over aux transactions (v2) paul@paul-NC210-NC110:~/linux-stable$ paul@paul-NC210-NC110:~/linux-stable$ git show 5fb9cc4d8b16 commit 5fb9cc4d8b1639b9a7487c1ee7b2b0c52877327d Author: Christian König <christian.koe...@amd.com> Date: Fri Apr 4 13:45:42 2014 +0200 drm/radeon: apply more strict limits for PLL params v2 Letting post and refernce divider get to big is bad for signal stability. v2: increase the limit to 210 Signed-off-by: Christian König <christian.koe...@amd.com> diff --git a/drivers/gpu/drm/radeon/radeon_display.c b/drivers/gpu/drm/radeon/radeon_display.c index 386cfa4c194d..2f42912031ac 100644 --- a/drivers/gpu/drm/radeon/radeon_display.c +++ b/drivers/gpu/drm/radeon/radeon_display.c @@ -937,6 +937,9 @@ void radeon_compute_pll_avivo(struct radeon_pll *pll, } post_div = post_div_best; + /* limit reference * post divider to a maximum */ + ref_div_max = min(210 / post_div, ref_div_max); + /* get matching reference and feedback divider */ ref_div = max(den / post_div, 1u); fb_div = nom; paul@paul-NC210-NC110:~/linux-stable$ I might try to recompile kernel with that line commented out. But it has been many years I did not compile a kernel. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1791312 Title: ubuntu 18.04 flickering screen with Radeon X1600 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1791312/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs