Ubuntu
linux package

  1. Bug #1821564
  2. Comment #10

Comment 10 for bug 1821564

Revision history for this message
Boris Gjenero (boris-gjenero) wrote :

This problem still exists in Ubuntu Focal Fossa (development branch) 20.04 with linux-image-5.4.0-21-generic. It also exists in linux-image-unsigned-5.6.2-050602-generic_5.6.2-050602.202004020822_amd64.deb

With linux-image-5.4.0-21-generic I didn't get any error messages after "insmod b44" in recovery mode. Also I normally booted linux-image-5.4.0-21-generic with mem=1G (limiting available memory to 1 GB) twice and also didn't get error messages after "sudo insmod b44". These symptoms are consistent with the hypothesis that swiotlb bounce buffers normally get allocated above 1 GB, causing a problem for b44 because the device can't do DMA above 1 GB and the driver can't handle this situation. That's the same problem discussed in this thread from 2011 https://groups.google.com/forum/#!topic/linux.kernel/GEx80ZCue1o

Obviously limiting memory to 1 GB has an unacceptable performance penalty, but it's nice to have at least one way to get working Ethernet.