It looks like this is a consequence of recent changes in the kernel that allow the system to optionally skip VT switches on suspend and resume:
24576d2 drm/i915: enable VT switchless resume v3 3cf2667 fb: add support for drivers not needing VT switch at suspend/resume time f43f627 PM: make VT switching to the suspend console optional v3 The kernel will not skip VT switches if no drivers register their VT switch requirements through pm_vt_switch_required(); however, if any drivers do so, and all of them indicate that VT switches are not required, they will be skipped. In the PRIME case, this is exactly what happens: the Intel driver registers itself as not needing VT switches, and the NVIDIA driver does not register its VT switch requirements one way or the other (the NVIDIA driver *does* need a VT switch on suspend/resume), so the kernel skips the VT switch, resulting in corruption when attempting to restore the NVIDIA X screen. The NVIDIA driver can be updated to pm_vt_switch_required() (I verified with a quick spot check that doing so restores the desired behavior: more testing will be needed before this change can be made officially); in the meantime, it is possible to work around this issue by adding 'no_console_suspend' to the kernel command line. -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to nvidia-prime in Ubuntu. https://bugs.launchpad.net/bugs/1210077 Title: Screen freeze and garbled after resume from suspend Status in HWE Next Project: Triaged Status in “nvidia-prime” package in Ubuntu: Confirmed Bug description: Perform regular suspend, either from system menu or close laptop lid, when system resuming from suspend, it will freeze. Switch to VT and back to X can solve freeze issue, but the screen are gabled and some character rendering are strange, however whole system can perform usual task. found affected graphics: gf108m gf117m gk107glm To manage notifications about this bug go to: https://bugs.launchpad.net/hwe-next/+bug/1210077/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp
