The Lantiq DSL drivers allow to log debug information via netlink multicast. This provides a small utility to read the log output which can be built as an OpenWrt package.
Logging via netlink can be enabled in the MEI driver like this:
echo DBG_LOGGER 1 > /proc/driver/mei_cpe/config
The amount of log output depends on the log level, which is a value from 4 to 1 (where 4 means no logging and 1 means full logging):
echo LOG 1 > /proc/driver/mei_cpe/config
echo TRACE 1 > /proc/driver/mei_cpe/config
Unfortunately, the MEI driver is actually broken which can result in a kernel crash.
The patch mei-fix-netlink-debug-logger.patch fixes this issue.