Trying to find the reason for this issue I tested kernels from https://kernel.ubuntu.com/~kernel-ppa/mainline/ on Ubuntu 14.04
v4.0.9-wily - flickering didn't happen (but that's because DRRS wasn't activated in the 4.0.y series) v4.1-rc3-unstable - problem started here. So it's quite possible that on a particular machine this issue is present since v4.1-rc1 I found that this is DRRS by looking at i915 commits in the 4.1.y tree. https://github.com/gregkh/linux/commits/linux-4.1.y/drivers/gpu/drm/i915/ intel_pc.c and intel_display.c have some DRRS-related changes I can try to revert some commits from there. Some interesting commits: * drm/i915: Add support for DRRS in intel_dp_set_m_n (https://github.com/gregkh/linux/commit/fe3cd48d6b616efc76b6a4003e82e933618c788a#diff-83261d1489be7f0a6d1b8306ff0fddbeb13ceb74768ea99274b009dce13ffd2e) * drm/i915/bdw: Add support for DRRS to switch RR (https://github.com/gregkh/linux/commit/a4c30b1d108c1ef60667ed357af4aeabc3d05eca#diff-83261d1489be7f0a6d1b8306ff0fddbeb13ceb74768ea99274b009dce13ffd2e) -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1928138 Title: Flickering on built-in display (Intel Haswell graphics) since kernel v4.1 [bisected and workaround attached] To manage notifications about this bug go to: https://bugs.launchpad.net/linux/+bug/1928138/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
