On Thu, 2018-04-12 at 09:48 +0800, Shawn Lin wrote: > I ran into 2 times that my system hung here when booting with a ext4 sd > card. No sure how to reproduce it but it seems doesn't matter with the > ext4 as I see it again with a vfat sd card, this morning with Linus' > master branch. Is it a known issue or any idea how to debug this? Please verify whether the following patch resolves this: https://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux-block.git/commit/?h=for-linus&id=37f9579f4c31a6d698dbf3016d7bf132f9288d30 Thanks, Bart.