From: https://kernel.ubuntu.com/~kernel-ppa/mainline/v3.15-rc2-trusty/CHANGES I see the folowing changes for radeon:
Alex Deucher (13): drm/radeon/dp: handle zero sized i2c over aux transactions (v2) drm/dp/i2c: send bare addresses to properly reset i2c connections (v4) drm/dp/i2c: Update comments about common i2c over dp assumptions (v3) drm/radeon/dp: switch to the common i2c over aux code drm/radeon: fix audio pin counts for DCE6+ (v2) drm/radeon: disable mclk dpm on R7 260X drm/radeon: fix runpm handling on APUs (v4) drm/radeon: update CI DPM powertune settings drm/radeon: add support for newer mc ucode on SI (v2) drm/radeon: add support for newer mc ucode on CI (v2) drm/radeon: re-enable mclk dpm on R7 260X asics drm/radeon/si: make sure mc ucode is loaded before checking the size drm/radeon/ci: make sure mc ucode is loaded before checking the size Christian König (2): drm/radeon: apply more strict limits for PLL params v2 drm/radeon: improve PLL params if we don't match exactly v2 Christoph Jaeger (2): ... drm/radeon: fix VCE fence command Quentin Casasnovas (1): drm/radeon: memory leak on bo reservation failure. v2 The: Christian König (2): drm/radeon: apply more strict limits for PLL params v2 drm/radeon: improve PLL params if we don't match exactly v2 rings a bell for me, because I believe someone somewhere was saying that a kernel parameter speaking of PLL was fixing the problem... but people did not find PLL parameters for radeon, so people did not follow about that comment. From: https://www.x.org/releases/current/doc/man/man4/radeon.4.xhtml I see: Option "LVDSProbePLL" "boolean" When BIOS panel information isn’t available (like on PowerBooks), it may still be necessary to use the firmware-provided PLL values for the panel or flickering will happen. This option will force probing of the current value programmed in the chip when X is launched in that case. This is only useful for LVDS panels (laptop internal panels). The default is on. Also: Option "DefaultTMDSPLL" "boolean" Use the default driver provided TMDS PLL values rather than the ones provided by the BIOS. This option has no effect on Mac cards. Enable this option if you are having problems with a DVI monitor using the internal TMDS controller. The default is off. Also: drm/radeon: update CI DPM powertune settings ring an other bell, because I think I remember someone saying something about DPM in some message. Sorry for not being more specific. A similar, older fixed closed bug: https://bugzilla.kernel.org/show_bug.cgi?id=26552 ** Bug watch added: Linux Kernel Bug Tracker #26552 https://bugzilla.kernel.org/show_bug.cgi?id=26552 -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1791312 Title: ubuntu 18.04 flickering screen with Radeon X1600 Status in linux package in Ubuntu: Confirmed Bug description: my laptop: HP Compaq nx9420 my grafic card: 01:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] RV530/M56-P [Mobility Radeon X1600] (prog-if 00 [VGA controller]) attachment: the bug-apport-file Description: I start ubuntu 18.04 LTS (Kernel 4.15.0.33) in textmode; -> as soon as the kernel-module radeon.ko is loaded the screen starts flickering when starting the grafic-mode the flickering continues; so the screen is unusable. when setting the option "radeon.modeset=0" (thus: not use radeon drivers) the screen does not flicker but the resolution is limited to 1400x1050 (instead of natural 1680x1050) so I can not use this as work-around when using the old ubuntu 14.04.05 LTS (Kernel 3.13.0-157) the screen is o.k. NO flickering in textmode, nice grafic, NO flickering xrandr tells: 1680x1050 60.1 so I must stay on old ubuntu 14.04.05 ??? To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1791312/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp