Using current Linus git head kernel, I was able to save the dmesg output: [ 17.218724] [drm] radeon kernel modesetting enabled. [ 17.218778] radeon 0000:00:01.0: vgaarb: deactivate vga console [ 17.219509] Console: switching to colour dummy device 80x25 [ 17.219700] [drm] initializing kernel modesetting (ARUBA 0x1002:0x990C 0x1002:0x0123 0x00). [ 17.219773] ATOM BIOS: 113 [ 17.219838] radeon 0000:00:01.0: VRAM: 768M 0x0000000000000000 - 0x000000002FFFFFFF (768M used) [ 17.219841] radeon 0000:00:01.0: GTT: 1024M 0x0000000030000000 - 0x000000006FFFFFFF [ 17.219844] [drm] Detected VRAM RAM=768M, BAR=256M [ 17.219845] [drm] RAM width 64bits DDR [ 17.219851] BUG: kernel NULL pointer dereference, address: 00000000000000a0 [ 17.219852] #PF: supervisor read access in kernel mode [ 17.219853] #PF: error_code(0x0000) - not-present page [ 17.219854] PGD 0 P4D 0 [ 17.219856] Oops: Oops: 0000 [#1] PREEMPT_RT SMP NOPTI [ 17.219858] CPU: 0 UID: 0 PID: 451 Comm: udevd Not tainted 6.11.0+ #6121 [ 17.219860] Hardware name: Gigabyte Technology Co., Ltd. To be filled by O.E.M./F2A78M-HD2, BIOS F2 05/28/2014 [ 17.219862] RIP: 0010:dma_get_required_mask+0x11/0x50 [ 17.219868] Code: 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 44 00 00 48 8b 87 68 02 00 00 48 85 c0 74 11 <48> 8b 80 a0 00 00 00 48 85 c0 74 1f e9 ee ed 94 00 f6 87 2c 03 00 [ 17.219870] RSP: 0018:ffffa54bc13a7b00 EFLAGS: 00010202 [ 17.219871] RAX: 0000000000000000 RBX: 000000ffffffffff RCX: 0000000000000000 [ 17.219872] RDX: 0000000000000000 RSI: 0000000000000027 RDI: ffff976f44e720c8 [ 17.219873] RBP: ffff976f44e720c8 R08: 00000000ffffefff R09: ffffffffab2aab08 [ 17.219874] R10: 00000000fffff000 R11: 0000000000000002 R12: 0000000000000000 [ 17.219875] R13: ffff976f48a4aa30 R14: 0000000000000000 R15: 0000000000000028 [ 17.219876] FS: 00007f59a070d840(0000) GS:ffff97726f800000(0000) knlGS:0000000000000000 [ 17.219878] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 17.219879] CR2: 00000000000000a0 CR3: 00000001053b4000 CR4: 00000000000406f0 [ 17.219880] Call Trace: [ 17.219881] <TASK> [ 17.219882] ? __die_body.cold+0x19/0x1e [ 17.219885] ? page_fault_oops+0xa8/0x230 [ 17.219889] ? search_module_extables+0x4f/0x90 [ 17.219891] ? fixup_exception+0x36/0x2f0 [ 17.219894] ? exc_page_fault+0x88/0x1b0 [ 17.219897] ? asm_exc_page_fault+0x22/0x30 [ 17.219900] ? dma_get_required_mask+0x11/0x50 [ 17.219902] dma_addressing_limited+0x6c/0xb0 [ 17.219905] radeon_ttm_init+0x3f/0x210 [radeon] [ 17.219977] cayman_init+0x97/0x290 [radeon] [ 17.220057] radeon_device_init+0x5e9/0xb40 [radeon] [ 17.220115] radeon_driver_load_kms+0xb0/0x260 [radeon] [ 17.220174] radeon_pci_probe+0xff/0x170 [radeon] [ 17.220231] pci_device_probe+0xbe/0x1a0 [ 17.220234] really_probe+0xde/0x350 [ 17.220237] ? pm_runtime_barrier+0x61/0xb0 [ 17.220240] ? __pfx___driver_attach+0x10/0x10 [ 17.220242] __driver_probe_device+0x78/0x110 [ 17.220245] driver_probe_device+0x2d/0xc0 [ 17.220247] __driver_attach+0xc9/0x1c0 [ 17.220249] bus_for_each_dev+0x6a/0xb0 [ 17.220251] ? migrate_enable+0xbf/0xf0 [ 17.220254] bus_add_driver+0x139/0x220 [ 17.220256] driver_register+0x6e/0xc0 [ 17.220258] ? __pfx_radeon_module_init+0x10/0x10 [radeon] [ 17.220315] do_one_initcall+0x42/0x210 [ 17.220318] ? __kmalloc_cache_noprof+0x89/0x230 [ 17.220321] do_init_module+0x60/0x210 [ 17.220324] init_module_from_file+0x89/0xc0 [ 17.220326] __x64_sys_finit_module+0x142/0x390 [ 17.220329] do_syscall_64+0x47/0x110 [ 17.220331] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 17.220334] RIP: 0033:0x7f59a0625279 [ 17.220336] Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 77 6b 0d 00 f7 d8 64 89 01 48 [ 17.220337] RSP: 002b:00007ffd15ee7df8 EFLAGS: 00000246 ORIG_RAX: 0000000000000139 [ 17.220339] RAX: ffffffffffffffda RBX: 00005578ae660840 RCX: 00007f59a0625279 [ 17.220340] RDX: 0000000000000000 RSI: 00005578ae677fc0 RDI: 0000000000000011 [ 17.220341] RBP: 0000000000000000 R08: 00007f59a06fcb20 R09: 00005578ae640550 [ 17.220342] R10: 0000000000000040 R11: 0000000000000246 R12: 00005578ae677fc0 [ 17.220342] R13: 0000000000020000 R14: 00005578ae651750 R15: 0000000000000000 [ 17.220344] </TASK> [ 17.220345] Modules linked in: radeon(+) snd_hda_codec_hdmi snd_seq_midi snd_seq_midi_event snd_seq snd_hda_intel snd_intel_dspcfg snd_emu10k1 snd_hda_codec drm_ttm_helper ttm snd_util_mem drm_suballoc_helper snd_ac97_codec snd_hda_core drm_display_helper ac97_bus snd_rawmidi snd_hwdep snd_seq_device snd_pcm drm_kms_helper edac_mce_amd sha512_ssse3 sha512_generic k10temp sha256_ssse3 sha1_ssse3 drm aesni_intel snd_timer gf128mul crypto_simd cryptd acpi_cpufreq evdev pcspkr serio_raw emu10k1_gp gameport at24 regmap_i2c i2c_algo_bit snd video soundcore wmi button sp5100_tco ext4 crc32c_generic crc16 mbcache jbd2 uas usb_storage hid_generic usbhid hid sg sr_mod sd_mod cdrom ata_generic firewire_ohci crc32_pclmul crc32c_intel firewire_core crc_itu_t pata_atiixp i2c_piix4 i2c_smbus ahci r8169 libahci xhci_pci ohci_pci realtek libata mdio_devres ehci_pci ohci_hcd xhci_hcd scsi_mod ehci_hcd scsi_common usbcore libphy usb_common [ 17.220388] CR2: 00000000000000a0 [ 17.220390] ---[ end trace 0000000000000000 ]--- Happy to provide additional information and run tests. Regards, Arthur Marsh.
