Hi Daniel, I meant Linux 4.13 of course, sorry! Can you fix the description for me please? If not, I can resend the patch with the updated description. Let me add some context to my patch. My laptop is Dell Precision 7510 with dual graphics (Intel and Nvidia). The dock is connected to two monitors with DisplayPort cables. It used to be two identical Dell P2416D monitors with 2560x1440 resolution. One of the monitors is in the vertical position. I've been using Fedora 26 with 4.11 and 4.12 kernels for a long time with no problems. The only issue was that the outputs would change names on reboot (e.g. DP-1-1 would become DP-1-4). I solved it by configuring all combinations in Gnome display settings. I also copied the resulting monitors.xml to the gdm repository to have the correct orientation in gdm. A few days ago, I changed one of the 24-inch monitors (the horizontal one) with a wide Dell U3417W monitor with 3440x1440 resolution. The monitor would come up blank on some reboots (the monitor would show that it was not getting any signal and would go to power saving more). So I decided to update to Fedora 27 prerelease with 4.13 kernel. Things got even worse. The blank screen issue was not resolved, but I also started getting messages about circular dependencies: ====================================================== WARNING: possible circular locking dependency detected 4.13.3-300.fc27.x86_64 #1 Not tainted ------------------------------------------------------ Xorg/1032 is trying to acquire lock: (&dev->struct_mutex){+.+.+.}, at: [<ffffffffc00bddfa>] drm_gem_object_put_unlocked+0xa/0xb0 [drm] but task is already holding lock: (reservation_ww_class_mutex){+.+.+.}, at: [<ffffffffc0329cc2>] validate_init.isra.5+0x202/0x740 [nouveau] which lock already depends on the new lock. I tried the current mainline kernel (4.14-rc1 at that time), and it started making oopses in nouveau_fbcon_set_suspend_work(). It that point, I wasn't using the dock. Then I realized that the 4.14-rc1 kernel wasn't showing "nouveaufb" in the log, whereas 4.13 was. The 4.14-rc1 kernel registers nouveaufb only if I use the dock. I tracked the issue to nouveau_fbcon_accel_save_disable() trying to dereference drm->fbcon->helper.fbdev which was NULL. Once I fixed nouveau_fbcon_accel_save_disable(), oops started happening in nouveau_fbcon_accel_restore(), which I fixed as well. I haven't seen oopses in nouveau_fbcon_accel_fini(), but maybe it's just because that code wasn't called, so I added a check there as well. Then I read the description of commit 52dfcc5ccfbb ("drm/nouveau: fix for disabled fbdev emulation") and decided to try Linux 4.13 with CONFIG_DRM_FBDEV_EMULATION disabled. As expected, it was oopsing without my patch (without the dock). I've been running the patched Linux kernels (now 4.14-rc2) for a day with no issues other than the blank screen. I work it around by changing the display orientation in display properties to portrait and back to landscape. I hope to get it fixed, but let's deal with the oops for now. I'm thinking of bisecting the circular dependency issue to get it backported to Linux 4.13. That would benefit other Fedora 27 users. If you know what patch fixed it, you would save me some time. Pavel _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel