Hi Joseph, Thanks a lot for your help. I have installed kernel 4.6rc4 as recommended today and booted into same issue. Find excerpt of dmesg output here:
[ 12.499797] BUG: unable to handle kernel NULL pointer dereference at 0000012c [ 12.500022] IP: [<c17b5572>] mutex_lock+0x12/0x30 [ 12.500022] *pdpt = 0000000035ff7001 *pde = 0000000000000000 [ 12.500022] Oops: 0002 [#1] SMP [ 12.500022] Modules linked in: nfsd auth_rpcgss nfs_acl lockd parport_pc grace ppdev sunrpc lp parport autofs4 pata_acpi hid_generic hid_cherry usbhid hid psmouse sdhci_pci r8169 pata_sch gma500_gfx sdhci i2c_algo_bit drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops drm mii fjes video [ 12.500022] CPU: 0 PID: 265 Comm: plymouthd Not tainted 4.6.0-040600rc4-generic #201604172330 [ 12.500022] Hardware name: CompuLab CM-iAM/SBC-FITPC2i/CM-iAM/SBC-FITPC2i, BIOS NAPA0001.86C.0000.D.1009141059 09/14/2010 [ 12.500022] task: f5f95a00 ti: f3570000 task.ti: f3570000 Thanks a lot for your support regards Hans-Jürgen [ 12.500022] EIP: 0060:[<c17b5572>] EFLAGS: 00010286 CPU: 0 [ 12.500022] EIP is at mutex_lock+0x12/0x30 [ 12.500022] EAX: 0000012c EBX: 0000012c ECX: 00000000 EDX: 80000000 [ 12.500022] ESI: 00000000 EDI: 00000000 EBP: f3571e90 ESP: f3571e8c [ 12.500022] DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 [ 12.500022] CR0: 80050033 CR2: 0000012c CR3: 35ca87e0 CR4: 000006f0 [ 12.500022] Stack: [ 12.500022] f5ca82a0 f3571ea0 f8534761 f1a73900 f5e18c00 f3571eb4 f84fa450 f5e18c00 [ 12.500022] f5e18c00 f5e18c00 f3571ec4 f8b070b9 f5e18c00 f5e18c34 f3571edc f8518b6a [ 12.500022] f756b098 00000000 00000000 f5e18c00 f3571f18 f8518ee7 00000000 00001000 [ 12.500022] Call Trace: [ 12.500022] [<f8534761>] drm_modeset_lock_all+0x31/0xb0 [drm] [ 12.500022] [<f84fa450>] drm_fb_helper_restore_fbdev_mode_unlocked+0x20/0x70 [drm_kms_helper] [ 12.500022] [<f8b070b9>] psb_driver_lastclose+0x19/0x50 [gma500_gfx] [ 12.500022] [<f8518b6a>] drm_lastclose+0x2a/0x140 [drm] [ 12.500022] [<f8518ee7>] drm_release+0x267/0x450 [drm] [ 12.500022] [<c11eb0c1>] __fput+0xd1/0x210 [ 12.500022] [<c11eb23d>] ____fput+0xd/0x10 [ 12.500022] [<c108ba7f>] task_work_run+0x7f/0xa0 [ 12.500022] [<c1003115>] exit_to_usermode_loop+0xd5/0xe0 [ 12.500022] [<c10039e7>] do_fast_syscall_32+0x127/0x140 [ 12.500022] [<c17b7c6a>] sysenter_past_esp+0x47/0x75 [ 12.500022] Code: 00 00 c3 8d b6 00 00 00 00 31 c0 5d c3 8d b6 00 00 00 00 8d bf 00 00 00 00 55 89 e5 53 3e 8d 74 26 00 89 c3 e8 70 ef ff ff 89 d8 <f0> ff 08 79 05 e8 74 07 00 00 64 a1 68 d2 c7 c1 89 43 10 5b 5d [ 12.500022] EIP: [<c17b5572>] mutex_lock+0x12/0x30 SS:ESP 0068:f3571e8c [ 12.500022] CR2: 000000000000012c [ 12.845872] ---[ end trace 92f73bfbf19bea01 ]--- -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1567781 Title: unable to handle kernel NULL pointer dereference at 00000134 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1567781/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
