Jean-Louis Dupond, thank you for reporting this and helping make Ubuntu better. Thank you for taking the time to report this bug and helping to make Ubuntu better. Please execute the following command, as it will automatically gather debugging information, in a terminal: apport-collect 1374607 When reporting bugs in the future please use apport by using 'ubuntu-bug' and the name of the package affected. You can learn more about this functionality at https://wiki.ubuntu.com/ReportingBugs.
** Tags added: bisect-done ** Changed in: linux (Ubuntu) Importance: Undecided => Low ** Changed in: linux (Ubuntu) Status: New => Incomplete -- 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/1374607 Title: nouveau - HDMI gives no more signal since 3.15 (optimus) Status in The Linux Kernel: Confirmed Status in “linux” package in Ubuntu: Incomplete Bug description: This week I tried HDMI again on my system, and noticed it was completely broken. Got just no signal on my screen. I knew it was working some months (and upgrades) ago. After testing I found out the issue was introduced between kernel v3.14 and v3.15. Situation: Insert HDMI cable into my laptop, and no signal on the external display. The dmesg fills with errors also: [ 186.210622] nouveau E[ PDISP][0000:01:00.0] INVALID_STATE [UNK08] chid 0 mthd 0x0080 data 0x00000000 [ 186.210627] nouveau E[ PDISP][0000:01:00.0] Core: [ 186.210634] nouveau E[ PDISP][0000:01:00.0] 0x0084: 0x5dc34da1 -> 0x80000000 [ 186.210640] nouveau E[ PDISP][0000:01:00.0] 0x0088: 0x00000000 etc. After some git bisect playtime, I found out the following commit caused the issue: https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/drivers/gpu/drm/nouveau?id=05c63c2ff23a80b654d6c088ac3ba21628db0173 So I went back to stable 3.16 (Ubuntu Utopic version), and did a git revert for that commit. And yep, HDMI output was working again, and no more nouveau errors in dmesg. My device: [ 30.823267] nouveau [ DEVICE][0000:01:00.0] BOOT0 : 0x0c1a00a1 [ 30.823269] nouveau [ DEVICE][0000:01:00.0] Chipset: GF108 (NVC1) [ 30.823270] nouveau [ DEVICE][0000:01:00.0] Family : NVC0 Laptop dell xps 15 l502x So this can be fixed with just reverting this commit. Else this is an annoying regression in Utopic. To manage notifications about this bug go to: https://bugs.launchpad.net/linux/+bug/1374607/+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