4.15 kernel won't support B43 or B44 network drivers

11 February 2018, 17:08:48

I started to install Artix on this box some months ago, and then let it sit, using a different distro in a separate partition. Yesterday I finally rebooted Artix and fully updated. If I boot to the lts kernel (4.14.8-1-lts) everything is fine, including my Broadcom Limited BCM4401-B0 100Base-TX (rev 02) ethernet, using the B44 kernel module. Unfortunately, if I boot to the "linux" kernel (4.15.0-1-ARTIX) my ethernet simply wont start. No errors, just no go. I can do "modprobe b44" with no error, and b44 shows up in lsmod, but no ethernet.

I was looking at differences in the two kernel /proc/config.gz files, but actually found https://patchwork.kernel.org/patch/10185397/ which shows it's a known problem, an unintended side effect of a MIPS related change. The driver is still present, but will never be enabled, due to requiring a different parameter, only present on MIPS. (I have an amd64.) Apparently the fix will not be in 4.15, but only 4.16. (I have not yet actually looked to see if it is fixed in 4.15.1 or 4.15.2.)

Does Artix ever patch kernels? Is there any point in submitting a bug report, since it's a known upstream issue? Would my only option for using 4.15 be to compile it myself?

EDIT: I confirm that the patch (one line) in that link above works - I'm now running a custom 4.15 with network access with the b44 kernel module.

Re: 4.15 kernel won't support B43 or B44 network drivers

Reply #1 – 14 February 2018, 21:03:32

We don't patch kernels or other software in general, unless absolutely necessary. Artix being a rolling release means that once upstream patch/fix their sources, we'll put the packages in the repos soonest.

Re: 4.15 kernel won't support B43 or B44 network drivers

Reply #2 – 19 February 2018, 18:39:59

(Why am I not getting email notifications of replies to posts which I am watching? I don't check often enough.)

While I do understand the reluctance to patch, in this case, it means anyone with a broadcom network chip using b44 module will not have any network if using any 4.15 kernel. I just confirmed this with 4.15.3. It is certainly not a huge issue, but it means I need to use linux-lts or else my own compiled kernel until 4.16 becomes available. Also, in this case, the patch changes only one line in the source. I don't know if there are really very few users of the b44 module, or if others who run into this will just fall back to the lts kernel.