I faced the same issue with an embedded LEX 2I260D-H26 on Ubuntu 16.04 both in kernels 4.6. I faced an issue where (when not blacklisting the gma500_gfx driver via /etc/modprobe.d/blacklist.conf), the HDMI screen would stay black, unless the HDMI cable was NOT plugged in during boot in which case I could connect HDMI after startup and then restart the display manager.
Also, the setup worked perfectly fine on a 1280x720 monitor (which does not support Full HD), but displayed the abovementioned failure modes in Full HD. I don't know if the dmesg error message also appears on the 1280x720 monitor, but it appeared if and only if the HDMI stayed black. I have solved this issue in Kernel 4.6 mainline (I have not tried with other kernels so far, but I will try with 4.4 in the next few weeks) by applying the following settings in "VGA setting" in the BIOS: On-Chip Frame Buffer Size := 64 MB (default: 8 MB) Total GFX Memory := 256 MB (default: 128 MB) I have not checked if any of those settings individually solve the issue. In any case, however, I believe it might be an issue with lack of memory, possibly either in the driver or in the firmware. It might also be related to a memory overflow/use-after-free etc that is triggered by the lack of memory. My recommended procedure to fix the issue on your hardware is to go into your BIOS and increase all memory settings for the embedded graphics until the problem disappears. I hope this information can help you debug it in your system. -- 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/1567781 Title: unable to handle kernel NULL pointer dereference at 00000134 Status in linux package in Ubuntu: Incomplete Bug description: Problem is found in dmesg output: [ 11.660671] BUG: unable to handle kernel NULL pointer dereference at 00000134 [ 11.660688] IP: [<c17692b2>] mutex_lock+0x12/0x30 [ 11.660706] *pdpt = 0000000033ee5001 *pde = 0000000000000000 [ 11.660714] Oops: 0002 [#1] SMP [ 11.660723] Modules linked in: nfsd auth_rpcgss nfs_acl lockd parport_pc grace ppdev lp sunrpc parport autofs4 hid_generic hid_cherry pata_acpi usbhid hid psmouse gma500_gfx i2c_algo_bit r8169 drm_kms_helper drm sdhci_pci pata_sch sdhci mii video [ 11.660772] CPU: 1 PID: 242 Comm: plymouthd Not tainted 4.2.0-35-generic #40-Ubuntu [ 11.660779] Hardware name: CompuLab CM-iAM/SBC-FITPC2i/CM-iAM/SBC-FITPC2i, BIOS NAPA0001.86C.0000.D.1009141059 09/14/2010 [ 11.660785] task: f5cf08c0 ti: f2364000 task.ti: f2364000 [ 11.660792] EIP: 0060:[<c17692b2>] EFLAGS: 00010286 CPU: 1 [ 11.660798] EIP is at mutex_lock+0x12/0x30 [ 11.660804] EAX: 00000134 EBX: 00000134 ECX: 00000000 EDX: 80000000 [ 11.660810] ESI: 00000000 EDI: 00000000 EBP: f2365ea8 ESP: f2365ea4 [ 11.660815] DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 [ 11.660820] CR0: 80050033 CR2: 00000134 CR3: 31a1d540 CR4: 000006f0 [ 11.660824] Stack: [ 11.660828] f19f93a0 f2365ec0 f8586171 f326dea0 f1ad7000 00000000 f1a0a400 f2365ec8 [ 11.660842] f858621f f2365edc f845ff47 f1a0a400 f1a0a400 f1a0a400 f2365eec f84b6019 [ 11.660856] f2365f04 c11b2de4 f2365f04 f856a78a f74d59d0 00000000 00000000 f1a0a400 [ 11.660869] Call Trace: [ 11.660935] [<f8586171>] __drm_modeset_lock_all+0x91/0x130 [drm] [ 11.660986] [<f858621f>] drm_modeset_lock_all+0xf/0x30 [drm] [ 11.661018] [<f845ff47>] drm_fb_helper_restore_fbdev_mode_unlocked+0x17/0x50 [drm_kms_helper] [ 11.661048] [<f84b6019>] psb_driver_lastclose+0x19/0x50 [gma500_gfx] [ 11.661060] [<c11b2de4>] ? kfree+0x134/0x140 [ 11.661110] [<f856a78a>] drm_lastclose+0x2a/0x140 [drm] [ 11.661159] [<f856ab3f>] drm_release+0x29f/0x490 [drm] [ 11.661170] [<c11cd0af>] __fput+0xcf/0x210 [ 11.661179] [<c11cd22d>] ____fput+0xd/0x10 [ 11.661189] [<c10869af>] task_work_run+0x7f/0xa0 [ 11.661200] [<c1012035>] do_notify_resume+0x75/0x80 [ 11.661209] [<c176bbcb>] work_notifysig+0x16/0x1b [ 11.661215] 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 60 ef ff ff 89 d8 <f0> ff 08 79 05 e8 74 07 00 00 64 a1 c8 c0 bf c1 89 43 10 5b 5d [ 11.661311] EIP: [<c17692b2>] mutex_lock+0x12/0x30 SS:ESP 0068:f2365ea4 [ 11.661323] CR2: 0000000000000134 [ 11.661332] ---[ end trace 3bb80835d39a3e44 ]--- ProblemType: Bug DistroRelease: Ubuntu 15.10 Package: linux-image-4.2.0-35-generic 4.2.0-35.40 ProcVersionSignature: Ubuntu 4.2.0-35.40-generic 4.2.8-ckt5 Uname: Linux 4.2.0-35-generic i686 ApportVersion: 2.19.1-0ubuntu5 Architecture: i386 AudioDevicesInUse: Error: command ['fuser', '-v', '/dev/snd/by-path', '/dev/snd/hwC0D0', '/dev/snd/pcmC0D2c', '/dev/snd/pcmC0D1p', '/dev/snd/pcmC0D0c', '/dev/snd/pcmC0D0p', '/dev/snd/controlC0', '/dev/snd/seq', '/dev/snd/timer'] failed with exit code 1: Date: Fri Apr 8 08:21:26 2016 HibernationDevice: RESUME=UUID=fda9b258-61a9-4bc5-974e-738538cee628 InstallationDate: Installed on 2013-07-09 (1003 days ago) InstallationMedia: Lubuntu 13.04 "Raring Ringtail" - Release i386 (20130423.1) MachineType: CompuLab CM-iAM/SBC-FITPC2i ProcFB: 0 VESA VGA ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-35-generic root=UUID=41b7698f-f3fa-4940-8e13-9378c5021e90 ro quiet splash vt.handoff=7 RelatedPackageVersions: linux-restricted-modules-4.2.0-35-generic N/A linux-backports-modules-4.2.0-35-generic N/A linux-firmware 1.149.3 RfKill: 0: phy0: Wireless LAN Soft blocked: yes Hard blocked: no SourcePackage: linux UpgradeStatus: Upgraded to wily on 2015-12-23 (106 days ago) dmi.bios.date: 09/14/2010 dmi.bios.vendor: Phoenix Technologies LTD dmi.bios.version: NAPA0001.86C.0000.D.1009141059 dmi.board.name: CM-iAM/SBC-FITPC2i dmi.board.vendor: Intel Corporation dmi.board.version: 1.x dmi.chassis.asset.tag: No Asset Tag dmi.chassis.type: 1 dmi.chassis.vendor: OEM dmi.chassis.version: N/A dmi.modalias: dmi:bvnPhoenixTechnologiesLTD:bvrNAPA0001.86C.0000.D.1009141059:bd09/14/2010:svnCompuLab:pnCM-iAM/SBC-FITPC2i:pvrNotApplicable:rvnIntelCorporation:rnCM-iAM/SBC-FITPC2i:rvr1.x:cvnOEM:ct1:cvrN/A: dmi.product.name: CM-iAM/SBC-FITPC2i dmi.product.version: Not Applicable dmi.sys.vendor: CompuLab To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1567781/+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
