故事开始于我尝试解决众所周知的 wifi 和蓝牙 (Ubuntu 14.04.5) 之间的冲突时。
我在 Ubuntu 论坛上找到了一个潜在的解决方案并应用了它。
命令 ：
echo "options iwlwifi 11n_disable=1 bt_coex_active=0 power_save=0 auto_agg=0 swcrypto=1" | sudo tee /etc/modprobe.d/iwlwifi.conf > /dev/null
重启后，wifi 无法使用。网上搜索了很多方法，但都无济于事。
我在原有版本旁边安装了另一个 14.04 Ubuntu，使用新版本启动后 Wifi 可以正常工作，因此硬件 100% 正常。
然后我将原来的“无法使用的 wifi”14.04 升级到 16.04，问题仍然存在，wifi 无法工作。
ifconfig wlan0 down并且up也尝试了几次。
值得一提的是eth0（通过电缆）我可以连接网络连接。
$ ifconfig
eth0
Link encap:Ethernet HWaddr 20:6a:8a:92:88:77
UP BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)
Interrupt:17
lo
Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:65536 Metric:1
RX packets:532 errors:0 dropped:0 overruns:0 frame:0
TX packets:532 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1
RX bytes:41984 (41.9 KB) TX bytes:41984 (41.9 KB)
wlan0
Link encap:Ethernet HWaddr c8:f7:33:55:0a:46
UP BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)
$ lsmod
Module Size Used by
rfcomm 69632 12
snd_hrtimer 16384 1
bnep 20480 2
binfmt_misc 20480 1
nls_iso8859_1 16384 1
uvcvideo 90112 0
videobuf2_vmalloc 16384 1 uvcvideo
arc4 16384 2
iwldvm 233472 0
videobuf2_memops 16384 1 videobuf2_vmalloc
videobuf2_v4l2 28672 1 uvcvideo
videobuf2_core 36864 2 uvcvideo,videobuf2_v4l2
mac80211 737280 1 iwldvm
acer_wmi 20480 0
cdc_mbim 16384 0
sparse_keymap 16384 1 acer_wmi
v4l2_common 16384 1 videobuf2_v4l2
cdc_wdm 20480 2 cdc_mbim
videodev 176128 4 uvcvideo,v4l2_common,videobuf2_core,videobuf2_v4l2
cdc_ncm 32768 1 cdc_mbim
intel_rapl 20480 0
usbnet 45056 2 cdc_mbim,cdc_ncm
mii 16384 1 usbnet
media 24576 2 uvcvideo,videodev
x86_pkg_temp_thermal 16384 0
intel_powerclamp 16384 0
coretemp 16384 0
kvm_intel 172032 0
iwlwifi 200704 1 iwldvm
kvm 540672 1 kvm_intel
btusb 45056 0
btrtl 16384 1 btusb
btbcm 16384 1 btusb
btintel 16384 1 btusb
irqbypass 16384 1 kvm
bluetooth 520192 39 bnep,btbcm,btrtl,btusb,rfcomm,btintel
snd_hda_codec_hdmi 53248 1
snd_hda_codec_conexant 24576 1
cfg80211 565248 3 iwlwifi,mac80211,iwldvm
snd_hda_codec_generic 77824 1 snd_hda_codec_conexant
snd_hda_intel 36864 3
snd_hda_codec 135168 4 snd_hda_codec_hdmi,snd_hda_codec_conexant,snd_hda_codec_generic,snd_hda_intel
snd_hda_core 73728 5 snd_hda_codec_hdmi,snd_hda_codec_conexant,snd_hda_codec_generic,snd_hda_codec,snd_hda_intel
snd_hwdep 16384 1 snd_hda_codec
crct10dif_pclmul 16384 0
snd_pcm 106496 4 snd_hda_codec_hdmi,snd_hda_codec,snd_hda_intel,snd_hda_core
snd_seq_midi 16384 0
crc32_pclmul 16384 0
snd_seq_midi_event 16384 1 snd_seq_midi
snd_rawmidi 32768 1 snd_seq_midi
snd_seq 69632 3 snd_seq_midi_event,snd_seq_midi
rtsx_pci_ms 20480 0
memstick 20480 1 rtsx_pci_ms
snd_seq_device 16384 3 snd_seq,snd_rawmidi,snd_seq_midi
snd_timer 32768 3 snd_hrtimer,snd_pcm,snd_seq
snd 81920 18 snd_hwdep,snd_timer,snd_hda_codec_hdmi,snd_hda_codec_conexant,snd_pcm,snd_seq,snd_rawmidi,snd_hda_codec_generic,snd_hda_codec,snd_hda_intel,snd_seq_device
cryptd 20480 0
soundcore 16384 1 snd
joydev 20480 0
input_leds 16384 0
mei_me 36864 0
dell_smo8800 16384 0
serio_raw 16384 0
shpchp 36864 0
mei 98304 1 mei_me
lpc_ich 24576 0
mac_hid 16384 0
cuse 16384 3
parport_pc 32768 0
ppdev 20480 0
lp 20480 0
parport 49152 3 lp,ppdev,parport_pc
autofs4 40960 2
rtsx_pci_sdmmc 24576 0
i915 1208320 3
tg3 163840 0
psmouse 126976 0
ptp 20480 1 tg3
i2c_algo_bit 16384 1 i915
pps_core 20480 1 ptp
drm_kms_helper 147456 1 i915
ahci 36864 4
syscopyarea 16384 1 drm_kms_helper
libahci 32768 1 ahci
sysfillrect 16384 1 drm_kms_helper
rtsx_pci 53248 2 rtsx_pci_ms,rtsx_pci_sdmmc
sysimgblt 16384 1 drm_kms_helper
fb_sys_fops 16384 1 drm_kms_helper
drm 364544 5 i915,drm_kms_helper
wmi 20480 1 acer_wmi
fjes 28672 0
video 40960 2 i915,acer_wmi
$ iwconfig
lo no wireless extensions.
wlan0 IEEE 802.11abg ESSID:off/any
Mode:Managed Access Point: Not-Associated Tx-Power=15 dBm
Retry short limit:7 RTS thr:off Fragment thr:off
Power Management:off
wwp0s26u1u1c2 no wireless extensions.
eth0 no wireless extensions
$ lshw
*-network
description: Wireless interface
product: Centrino Advanced-N 6235
vendor: Intel Corporation
physical id: 0
bus info: pci@0000:03:00.0
logical name: wlan0
version: 24
serial: c8:f7:33:55:0a:46
width: 64 bits
clock: 33MHz
capabilities: pm msi pciexpress bus_master cap_list ethernet physical wireless
configuration: broadcast=yes driver=iwlwifi driverversion=4.4.0-38-generic firmware=18.168.6.1 latency=0 link=no multicast=yes wireless=IEEE 802.11abg
resources: irq:30 memory:f1500000-f1501fff
# /etc/modprobe.d/iwlwifi.conf
# iwlwifi will dyamically load either iwldvm or iwlmvm depending on the
# microcode file installed on the system. When removing iwlwifi, first
# remove the iwl?vm module and then iwlwifi.
remove iwlwifi \
(/sbin/lsmod | grep -o -e ^iwlmvm -e ^iwldvm -e ^iwlwifi | xargs /sbin/rmmod) \
&& /sbin/modprobe -r mac80211
# options iwlwifi 11n_disable=1
# options iwlwifi swcrypto=1
# options iwlwifi 11n_disable=8
# options iwlwifi bt_coex_active=0 swcrypto=1 11n_disable=8
# options iwlwifi 11n_disable=1
如果有人能提供帮助，将不胜感激，
编辑：为了避免混淆，无线在使用命令之前就已经正常工作
echo "options iwlwifi 11n_disable=1 bt_coex_active=0 power_save=0 auto_agg=0 swcrypto=1" | sudo tee /etc/modprobe.d/iwlwifi.conf > /dev/null
答案1
逐行读取dmesg输出后，我发现我有一个文件badiwlwifi.conf存储在其中/etc/modprobe.d。问题出现后，我立即复制了错误的配置文件。
看来iwlwifi文件中的内容足以在启动时加以考虑。我今天学到了一些东西。