Hi Folks,
I've been fighting with an Intel branded ax200 160MHz Rev=0x340 for
several hours today. This is on Ubuntu 20.04 setup with the standard
ubuntu 5.8.0-53-generic kernel. Out of the gate I was seeing timeout
(-110) errors in various places in dmesg (The exact error depends on the
firmware version and module options, but always seemed to be some
manifestation of the same general problem). One example with the
default iwlwifi-cc-a0-55.ucode firmware:
iwlwifi 0000:03:00.0: Failed to set soc latency: -110
but potentially also:
iwlwifi 0000:03:00.0: PHY ctxt cmd error. ret=-110
After many failed attempts and a ton of trial and error, I was able to
get the driver loaded but only under very specific conditions:
1) The firmware must be iwlwifi-cc-a0-48.ucode (48.4fa0041f.0) or older.
All more recent versions I tried beginning with iwlwifi-cc-a0-50.ucode
would result in the same errors (including on the ubuntu 5.10 oem kernels).
2) iwlwifi-cc-a0-48 and older would only load with iwlmvm power_scheme=1
set as an option in /etc/modprobe.d/iwlwifi.conf.
That was enough to get the driver to load, but several other iwlwifi
options appear to be required to avoid instability and tainted kernels:
swcrypto=0 power_save=0. At one point I was still having issues with tx
fifo queue flushing, but that may have been related to using
backport-iwlwifi-dkms which I've since removed.
For now, I wanted to document the progress and fix for posterity and
also ask a question: Is a changelog for the iwlwifi firmware revisions
posted anywhere? The primary issue I was facing today seems to be
related to some change that occurred between iwlwifi-cc-a0-48 and
iwlwifi-cc-a0-50. So far I have had very little luck tracking down
what's different.
Thanks,
Mark
