Created attachment 135071 [details] dmesg broken 3.15-rc3 kernel I just have a black screen with frequency out of range on the monitor with the kernel 3.15-rc3.The system boot normaly but after 3 seconds wen it should display the splash screen comme the frequency out of range on the monitor, but the boot process continue in the dark as normal and the system is responsive. Everything work fine in 3.15-rc1 and rc2 kernels. I'm running Kubuntu 12.04 Precise. I have a RS880 motherboard with : 01:05.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] RS880 [Radeon HD 4200]. After bisecting the first bad commit found : first bad commit 24315814239a3fdb306244c99bd076bc79db4ade Auteur: Christian König <christian.koenig@amd.com> 2014-04-19 18:57:14 Auteur du commit: Christian König <christian.koenig@amd.com> 2014-04-19 18:57:14 Parent: 76e6dcece841faebbee78895780e8209ff40d922 (drm/radeon: disable dpm on rv770 by default) Branche: master, remotes/origin/master Suit: v3.15-rc1 Précède: v3.15-rc3 drm/radeon: use fixed PPL ref divider if needed Signed-off-by: Christian König <christian.koenig@amd.com> ------------------- drivers/gpu/drm/radeon/radeon_display.c ------------------- index 2f7cbb9..e6c3c54 100644 @@ -880,7 +880,12 @@ void radeon_compute_pll_avivo(struct radeon_pll *pll, ref_div_min = pll->reference_div; else ref_div_min = pll->min_ref_div; - ref_div_max = pll->max_ref_div; + + if (pll->flags & RADEON_PLL_USE_FRAC_FB_DIV && + pll->flags & RADEON_PLL_USE_REF_DIV) + ref_div_max = pll->reference_div; + else + ref_div_max = pll->max_ref_div; /* determine allowed post divider range */ if (pll->flags & RADEON_PLL_USE_POST_DIV) { But sadly reverting the patch and rebuild the kernel doesn't fix the issue. Attached are dmesg with drm_debug=0xe for the 3.15rc3 (broken) and 3.15-rc2 kernels, and also the bisect.log.
Created attachment 135081 [details] dmesg working 3.15-rc2 kernel
That's a duplicate of https://bugzilla.kernel.org/show_bug.cgi?id=75241
Oop's Ignore my first post, i must made a copy paste error somewhere ! The first bad commit is indeed this one : c2fb3094669a3205f16a32f4119d0afe40b1a1fd is the first bad commit commit c2fb3094669a3205f16a32f4119d0afe40b1a1fd Author: Christian König <christian.koenig@amd.com> Date: Sun Apr 20 13:24:32 2014 +0200 drm/radeon: improve PLL limit handling in post div calculation This improves the PLL parameters when we work at the limits of the allowed ranges. Signed-off-by: Christian König <christian.koenig@amd.com> I just revert the commit, rebuild and is working fine again now. Sorry for my first report.
Created attachment 135091 [details] git bisect 3.15-rc3 3.15-rc2 log