Question

3

Downgrading iwlwifi

rated 0 times [ 3] [ 0] / answers: 1 / hits: 5571 / 1 Year ago, mon, december 12, 2022, 6:25:28

I asked this question, but I'm becoming more and more certain that my problem stems from a faulty iwlwifi firmware version. Rather than muddy the water there, I'd like to ask if it's possible to downgrade my islwifi firmware to a previous version.

If it's possible, can you tell me specifically how? I'm not really great with generic instructions. Or is there a website that I've missed?

Answers

Only authorized users can answer the question. Please sign in first, or register a free account.

enytidge

Add To Favorites

Follow

Total Points: 169

Total Questions: 105

Total Answers: 107

Location: Papua New Guinea

Member since Tue, Aug 24, 2021

3 Years ago

enytidge questions

1 Applying netplan with both NetworkManager and networkd

Tue, Feb 28, 23, 15:26, 1 Year ago

1 How to get the snap-based chromium to access a separately mounted filesystem?

Mon, Apr 11, 22, 11:45, 2 Years ago

1 Mouse and keyboard freeze Ubuntu 20.04

Sun, Jan 1, 23, 19:36, 1 Year ago

1 In what way did I destroy my USB and how to repair it?

Sun, Oct 24, 21, 07:30, 3 Years ago

1 How to install Jio Meet on Ubuntu 20.04 LTS

Wed, Nov 9, 22, 22:02, 2 Years ago

View All

answered 1 Year ago wenceslockro · Accepted Answer

The Linux firmware sources are being developed in a Git repository, so it's easy to go back in time for all older releases of the firmware.

Install git

Clone the repository (cgit web page):

git clone http://git.kernel.org/pub/scm/linux/kernel/git/firmware/linux-firmware.git

cd into the repository:
```
cd linux-firmware
```

Locate the firmware for your device as per the iwlwifi development page or legacy (scroll down), e.g. iwlwifi-3945-2.ucode.
```
find . -name "iwlwifi*"
```
Notice that for some devices multiple versions are kept as separate files, for the compatibility of older kernel versions.

Have a look at the history of the file:

git log iwlwifi-3945-2.ucode

shows (removed some irrelevant lines):

commit d90a18c9e7eef19ab978c4c0bb2d2d4b8fa49dce

Date:   Thu May 14 18:15:50 2009 +0100



    linux-firmware: Update Intel Wireless Wifi 3945 firmware



    Version is now 15.32.2.9



commit caef650a8c909f557ed7f6b23c413401d6994fdb

Date:   Tue Jan 20 21:37:48 2009 +0000



    linux-firmware: Add Intel Wireless Wifi firmware

The revision at the top is the version in your working directory. To retrieve an older version of the same file, do this:
```
git show caef650a8c909f557ed7f6b23c413401d6994fdb iwlwifi-3945-2.ucode > ~/some/destination/iwlwifi-3945-2.ucode
```
see also: How to retrieve a single file from specific revision in Git?

However, most firmware files only have a single revision in the repository and are versioned by just having multiple filenames.

Install the firmware in /usr/local/lib/firmware (location for manually installed firmware files) by copying the file there:
```
sudo cp /path/to/iwlwifi-3945-2.ucode /usr/local/lib/firmware/
```

Remove and re-insert the kernel module(s):
```
rmmod iwldvm && rmmod iwlwifi

modprobe iwlwifi && modprobe iwldvm
```
And look at dmesg to see if the firmware gets loaded.

In case you wonder if any files have been removed from the repository, try this:

git log --diff-filter=D --summary | grep delete

At the time of writing, no Intel firmware has been deleted ever.