Description of problem: With kernel 3.18.2-200 I cannot play any videos in vlc any more, with kernel 3.17.* it works fine. As far as I tested this affects VLC. HTML5 video e.g. on youtube works fine on both kernels. This regression is known upstreams, see https://bugzilla.kernel.org/show_bug.cgi?id=90871 for details. To test wether you are affected simply look for the line (EE) intel(0): Failed to submit rendering commands, disabling acceleration. in your Xorg.log or syslog.
kernel-3.18.3-201.fc21 has been submitted as an update for Fedora 21. https://admin.fedoraproject.org/updates/kernel-3.18.3-201.fc21
Package kernel-3.18.3-201.fc21: * should fix your issue, * was pushed to the Fedora 21 testing repository, * should be available at your local mirror within two days. Update it with: # su -c 'yum update --enablerepo=updates-testing kernel-3.18.3-201.fc21' as soon as you are able to, then reboot. Please go to the following url: https://admin.fedoraproject.org/updates/FEDORA-2015-0937/kernel-3.18.3-201.fc21 then log in and leave karma (feedback).
kernel-3.18.3-201.fc21 has been pushed to the Fedora 21 stable repository. If problems still persist, please make note of it in this bug report.