Results 1 to 1 of 1

Thread: Ubuntu 20.04.6 wifi no longer starting

  1. #1
    Join Date
    Mar 2024
    Beans
    1

    Arrow Ubuntu 20.04.6 wifi no longer starting

    Ubuntu 20.04.6 with Ubuntu Pro, Mate 1.26 Kernel 5.15, Marco and lightdm (all fully up to date) running on Dell Precision M6800 (with latest firmware) Laptop i7-4600M with 16GB RAM and 250GB Kingston SA400S3 SSD

    Kernels installed: 5.15.0-97 with wifi no longer starting
    5.15.0-94 with no issues
    both kernels running on same ssd with common iwlwifi (and associated: dvm, mvm, ) driver files present and working under the -94 kernel version, but not getting loaded by the -97 boot.

    While running off my usual -97 kernel, problem started while investigating issues with regular Tilda crashes and some modules like the desktop selector crashing occasionally. Examination of logs indicated issues with the generic 'nouveau' driver with the nvidia card, and further investigation pointed to incompatibility with a recent Ubuntu or Kernel update? A disastrous and very long attempt to go to latest Nvidia driver lead to computer freezing and forced power down. All Nvidia drivers were purged and configuration re-established to use problem 'nouveau' driver, and was able to boot again into X. However a new problem appeared: the wifi no longer works. Investigation shows that the driver does not load anymore, but is present and correct version, as it works on exactly same computer with -94 kernel, and was working on the -97 kernel.

    I'm an advanced user of Ubuntu (15 years) but not an expert or programmer. Hacked at this little problem for 4 days with chatGPT4 to see if I could solve it on my own. Likely real experts hear will find this amount of time rediculous, but I don't quite know the innards of the the os, like details of the boot sequence between a GRUB 2 menu choice and the process of booting all the modules and kernels, etc. and what's amiss for the wifi module to be loaded. Amoung things tried:
    a) manually loading iwlwifi with modprobe
    b) purging the -97 kernel, re-installing kernel
    c) assumed a mystical reason why the iwlwifi driver would work with one kernel version and not the other so reloaded the latest version of the driver from Intel

    Attached in an archive are 3 files:
    1) system profile using the script system-info, with some details not pertinent removed (list of all software, ...) removed, but complete otherwise
    2) using the script wireless-info the results with the -94 and those for the -97 kernels;

    Likely the results of the following tests will also help:

    >>> tests run with -94 kernel

    ~$ lspci -nnk | grep -A2 0280
    03:00.0 Network controller [0280]: Intel Corporation Wireless 7260 [8086:08b1] (rev 73)
    Subsystem: Intel Corporation Dual Band Wireless-AC 7260 [8086:4470]
    Kernel driver in use: iwlwifi

    ~$ lspci -nnk | grep -A2 0280
    03:00.0 Network controller [0280]: Intel Corporation Wireless 7260 [8086:08b1] (rev 73)
    Subsystem: Intel Corporation Dual Band Wireless-AC 7260 [8086:4470]
    11:00.0 SD Host controller [0805]: O2 Micro, Inc. SD/MMC Card Reader Controller [1217:8520] (rev 01)


    >>> tests run with -97 kernel~$ sudo modprobe -v iwlwifi
    modprobe: ERROR: ../libkmod/libkmod-module.c:838 kmod_module_insert_module() could not find module by name='iwlwifi'
    modprobe: ERROR: could not insert 'iwlwifi': Unknown symbol in module, or unknown parameter (see dmesg)

    modinfo iwlwifi | grep depends
    ~$ modinfo iwlwifi | grep depends
    modinfo: ERROR: Module iwlwifi not found.

    grep -r iwlwifi /etc/modprobe.d/ /usr/lib/modprobe.d/
    /etc/modprobe.d/iwlwifi.conf:# /etc/modprobe.d/iwlwifi.conf
    /etc/modprobe.d/iwlwifi.conf:# iwlwifi will dyamically load either iwldvm or iwlmvm depending on the
    /etc/modprobe.d/iwlwifi.conf:# microcode file installed on the system. When removing iwlwifi, first
    /etc/modprobe.d/iwlwifi.conf:# remove the iwl?vm module and then iwlwifi.
    /etc/modprobe.d/iwlwifi.conf:remove iwlwifi \

    >>> in Summary:
    A) both kernel versions had wifi working, and the -97 wifi stopped working after a severe computer crash associated with an nvidia driver updated.
    B) the drivers are the latest correct versions and in the right place but the -97 kernel reports not finding them, yet they have not moved since it was previously working with the same kernel
    C) something in the boot process does not seem to be detecting the intel wifi card and triggering the driver(s) to load

    Now the commands above to generate those test results are from chatGPT4, as they are beyond my experience at this time. I've gone as far as I can go on my own and any help would be appreciated. Thanks very much.

    xian555
    Attached Files Attached Files

Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •