Hi Alexandre,
First bad commit (maybe != root cause):
tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: 0c2b6dc4fd4fa13796b319aae969a009f03222c6
commit: 3489187204eb75e5635d8836babfd0a18be613f4 serial: stm32: adding dma support
date: 4 weeks ago
config: m32r-allmodconfig (attached as .config)
compiler: m32r-linux-gcc (GCC) 6.2.0
reproduce:
wget https://git.kernel.org/cgit/linux/kernel/git/wfg/lkp-tests.git/plain/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
git checkout 3489187204eb75e5635d8836babfd0a18be613f4
# save the attached .config to linux build tree
make.cross ARCH=m32r
All errors (new ones prefixed by >>):
ERROR: "bad_dma_ops" [sound/soc/bcm/snd-soc-cygnus.ko] undefined!
ERROR: "bad_dma_ops" [sound/core/snd-pcm.ko] undefined!
ERROR: "dma_common_mmap" [sound/core/snd-pcm.ko] undefined!
ERROR: "bad_dma_ops" [drivers/tty/serial/stm32-usart.ko] undefined!