Assessing WiFi after switching back to the 5.9 kernel, it seems consistently better for both stability and general performance. I ended up going back to the 5.11 kernel to spend a little more time with it to be sure my previous observations were consistent and not down to some coincidental glitch. I also noticed that streaming audio via Bluetooth while simultaneously being connected via WiFi has also degraded a little.
Not sure how helpful or not this info is, however, I have a couple of different APs to work with (a MikroTik hAP ac^2 configured as a simple AP bridge serving 5Ghz and a Ubiquiti Nano HD serving 2.4Ghz) both of these along with a file server are connected to a switched bridge on a MikroTik RB4011 the topology is…
Librem5 <-> MikroTik hAP ac^2 <-> MikroTik RB4011 bridge <-> Intranet File Server
and…
Librem5 <-> Ubiquiti Nano HD <-> MikroTik RB4011 bridge <-> Intranet File Server
I tried various configurations and combinations of channel widths and available protocols on the hAP ac^2, there seemed to be no discernible difference. The Nano HD I just left as was which is 2.4Ghz b/g/n 20-40Mhz channel width, this AP drops to the lowest channel width of a single client so if there is one single client that can only operate on 20Mhz when all others can deal with 40Mhz, the AP will drop down to 20Mhz.
Pulling a batch of files (the same batch each time) of approximate 15-45MB in size I’m seeing the following…
Librem5 (5.9 kernel) via hAP ac^2 download 1.5~3.0MB/s
Librem5 (5.11 kernel) via hAP ac^2 download 500~650KB/s
Librem5 (5.9 kernel) via Nano HD download 300~400KB/s
Librem5 (5.11 kernel) via Nano HD download 120KB/s~timeout
Perhaps coincidental, while on the 5.11 kernel I experienced 2 phosh reboots and one unplanned/ungraceful shutdown, none of which were repeatable, I experience the same from time to time on 5.9 kernel but in such a short space of time. Touch/swipe to close apps from the application switcher seemed a little off too, on one occasion with the app thumbnail centered, swipe up was not recognised, I swiped right and was then able to swipe up on the left hand visible portion of the thumbnail to close the app, again, non repeatable.
I’ve decided to stay with the 5.9 kernel for the moment and my OCD also wanted to get APT back to being in the right state with regards tracking installed kernel packages as it was showing 5.11 installed but I was running the 5.9 kernel.
The rest of this post just details the steps I went through to put APT back to pre-upgrade state, you can skip the rest if it’s not something you want/need to do.
Although no longer available for straight forward install from the repos via apt-get, I found the kernel packages by browsing the repos online, so I first downloaded packages…
wget https://repo.pureos.net/pureos/pool/main/l/linux-librem5/linux-image-5.9.0-1-librem5_5.9.16+librem5.2_arm64.deb
wget https://repo.pureos.net/pureos/pool/main/l/linux-librem5/linux-image-librem5_5.9.16+librem5.2_arm64.deb
dpkg -I linux-image-librem5_5.9.16+librem5.2_arm64.deb
showed I only needed the second deb file as it listed a single dependency “linux-image-5.9.0-1-librem5” which is the first package I downloaded and dpkg -l | grep linux
showed it was already installed.
So I installed the file which in turn informs you that it will downgrade the linux-image-librem5 package…
sudo apt-get install ./linux-image-librem5_5.9.16+librem5.2_arm64.deb
…note the preceding “./” this is important and signals apt-get that it is installing from a local file.
After that I could remove the 5.11 kernel package…
sudo apt-get purge linux-image-5.11.0-1-librem5
…read the output of the above command very carefully before entering ‘Y’ to continue to make sure it is only removing the 5.11 kernel package, if there is any other package listed as to be removed you should probably enter ‘n’
After that, apt-cache policy linux-image-librem5
shows…
linux-image-librem5:
Installed: 5.9.16+librem5.2
Candidate: 5.11.4pureos1~amber1
Version table:
5.11.4pureos1~amber1 500
500 https://repo.pureos.net/pureos amber-phone main arm64 Packages
*** 5.9.16+librem5.2 100
100 /var/lib/dpkg/status
…which puts it back to pre-upgrade state, then all that remains is to hold it back so I don’t update inadvertently…
sudo apt-mark hold linux-image-librem5