我有一台 nvidia optimus 笔记本电脑（Thinkpad P50），我无法在一些最近的升级。
我设法将其调试为以下命令，但失败了：
$ cat /proc/acpi/bbswitch
[1] 4564 killed cat /proc/acpi/bbswitch
dmesg 打印以下内容：
[ 355.456388] BUG: unable to handle kernel NULL pointer dereference at 00000000000000c0
[ 355.456492] IP: pci_read_config_dword.part.13+0x4d/0x80
[ 355.456544] PGD 8000000fc8bec067
[ 355.456546] P4D 8000000fc8bec067
[ 355.456580] PUD f55200067
[ 355.456613] PMD 0
[ 355.456685] Oops: 0000 [#1] SMP PTI
[ 355.456721] Modules linked in: rfcomm bnep ipt_MASQUERADE nf_nat_masquerade_ipv4 nf_conntrack_netlink nfnetlink xfrm_user xfrm_algo iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 xt_addrtype iptable_filter ip_tables xt_conntrack x_tables nf_nat nf_conntrack libcrc32c br_netfilter bridge stp llc overlay nvidia_uvm(POE) nvidia_drm(POE) nvidia_modeset(POE) nvidia(POE) pci_stub vboxpci(OE) vboxnetadp(OE) vboxnetflt(OE) vboxdrv(OE) bbswitch(OE) binfmt_misc arc4 nls_iso8859_1 wmi_bmof intel_rapl x86_pkg_temp_thermal intel_powerclamp kvm_intel kvm irqbypass crct10dif_pclmul crc32_pclmul ghash_clmulni_intel pcbc aesni_intel snd_hda_codec_realtek iwlmvm aes_x86_64 snd_hda_codec_generic crypto_simd glue_helper cryptd mac80211 intel_cstate intel_rapl_perf snd_seq_midi btusb btrtl btbcm btintel snd_seq_midi_event
[ 355.457441] uvcvideo iwlwifi videobuf2_vmalloc videobuf2_memops bluetooth snd_hda_intel videobuf2_v4l2 videobuf2_core snd_rawmidi rtsx_pci_ms snd_hda_codec ecdh_generic serio_raw memstick cfg80211 videodev joydev thinkpad_acpi input_leds snd_hda_core media snd_hwdep nvram snd_pcm mei_me snd_seq mei ipmi_devintf ipmi_msghandler snd_seq_device intel_pch_thermal snd_timer shpchp ie31200_edac snd soundcore wmi tpm_crb mac_hid coretemp parport_pc ppdev lp parport autofs4 hid_generic usbhid hid i915 rtsx_pci_sdmmc i2c_algo_bit drm_kms_helper e1000e syscopyarea sysfillrect sysimgblt ptp fb_sys_fops psmouse pps_core rtsx_pci drm nvme ahci nvme_core libahci video [last unloaded: nvidia]
[ 355.458050] CPU: 6 PID: 4564 Comm: cat Tainted: P W OE 4.13.0-32-generic #35~16.04.1-Ubuntu
[ 355.458134] Hardware name: LENOVO 20ENCTO1WW/20ENCTO1WW, BIOS N1EET75W (1.48 ) 12/13/2017
[ 355.458210] task: ffff9984744a0000 task.stack: ffffa71708e24000
[ 355.458271] RIP: 0010:pci_read_config_dword.part.13+0x4d/0x80
[ 355.458327] RSP: 0018:ffffa71708e27de0 EFLAGS: 00010246
[ 355.458379] RAX: 0000000000000087 RBX: ffff99848546e780 RCX: 0000000000033f2d
[ 355.458446] RDX: ffffa71708e27e1c RSI: 0000000000000000 RDI: 0000000000000000
[ 355.463615] RBP: ffffa71708e27df8 R08: ffff9985615a5e00 R09: 00000000632d656c
[ 355.469188] R10: ffff9984627e4000 R11: ffff9984744a0000 R12: ffffa71708e27f18
[ 355.474200] R13: ffff99845a929a00 R14: 0000000000000001 R15: ffff99848546e780
[ 355.478988] FS: 00007fa647474700(0000) GS:ffff998561580000(0000) knlGS:0000000000000000
[ 355.483768] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 355.487648] CR2: 00000000000000c0 CR3: 000000104f9d0003 CR4: 00000000003606e0
[ 355.490853] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 355.493248] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 355.495616] Call Trace:
[ 355.497557] pci_read_config_dword+0x25/0x30
[ 355.499423] bbswitch_proc_show+0x37/0xa0 [bbswitch]
[ 355.501224] seq_read+0x9e/0x440
[ 355.502778] proc_reg_read+0x42/0x70
[ 355.504330] __vfs_read+0x18/0x40
[ 355.505871] vfs_read+0x93/0x130
[ 355.507177] SyS_read+0x55/0xc0
[ 355.508468] entry_SYSCALL_64_fastpath+0x33/0xa3
[ 355.509757] RIP: 0033:0x7fa646fa1260
[ 355.511016] RSP: 002b:00007fff1cf55718 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
[ 355.512161] RAX: ffffffffffffffda RBX: 0000000000020000 RCX: 00007fa646fa1260
[ 355.513291] RDX: 0000000000020000 RSI: 00007fa647478000 RDI: 0000000000000003
[ 355.514420] RBP: 0000000000020000 R08: ffffffffffffffff R09: 0000000000000000
[ 355.515520] R10: 000000000000037b R11: 0000000000000246 R12: 00007fa647478000
[ 355.516575] R13: 0000000000000003 R14: 0000000000000000 R15: 0000000000020000
[ 355.517570] Code: 48 89 45 f0 31 c0 40 f6 c6 03 48 8b 7f 10 b8 87 00 00 00 74 16 48 8b 4d f0 65 48 33 0c 25 28 00 00 00 75 29 48 83 c4 10 5b 5d c3 <48> 8b 87 c0 00 00 00 48 89 d3 4c 8d 45 ec 89 f2 b9 04 00 00 00
[ 355.518623] RIP: pci_read_config_dword.part.13+0x4d/0x80 RSP: ffffa71708e27de0
[ 355.519651] CR2: 00000000000000c0
[ 355.525470] ---[ end trace 8c2a4995d01b70ef ]---
更多信息
Ubuntu 16.04
$ uname -a
Linux frantisek-thinkpad 4.13.0-32-generic #35~16.04.1-Ubuntu SMP Thu Jan 25 10:13:43 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux
nvidia 驱动程序版本是 390.25-0ubuntu0~gpu16.04.1，但 384 和 387 也出现同样的情况。
在 11 月/12 月的某次更新之前，它一直运行良好。