The log_check WARNINGs with the 4.4 kernels is being addressed by bug 1965160 with commit 036e9ef8becd ("dmaengine: Replace WARN_TAINT_ONCE() with pr_warn_once()").
This commit has been applied upstream for v4.13-rc1, so from bionic+ we should have only the kernel tainted failure. However, that commit keeps the TAINT_FIRMWARE_WORKAROUND taint flag and this is still true for mainline, so probably this bug can't be fixed as this is a hardware issue.
The log_check WARNINGs with the 4.4 kernels is being addressed by bug 1965160 with commit 036e9ef8becd ("dmaengine: Replace WARN_TAINT_ONCE() with pr_warn_once()").
This commit has been applied upstream for v4.13-rc1, so from bionic+ we should have only the kernel tainted failure. However, that commit keeps the TAINT_FIRMWARE_ WORKAROUND taint flag and this is still true for mainline, so probably this bug can't be fixed as this is a hardware issue.