Dear Greg,
Our customers have feedback some similar issues as below link on Android kernel-4.14 and kernel-4.19. Link: https://marc.info/?l=linux-kernel&m=138695698516487
They've reported system become abnormal when OTG U-disk has been plugged out after the system has been suspended. After debugging, we've found the root cause is the same of the issue (link) has been reported. We've also tested the patch "bdi: Do not use freezable workqueue" is worked. Link: https://lkml.org/lkml/2019/10/4/176 commit id in Linus tree: a2b90f11217790ec0964ba9c93a4abb369758c26
However, we've checked that patch seems hasn't been applied to stable tree (We've checked 4.14 and 4.19). Would you please help to cherry-pick this patch to stable trees (and to Android trees)?
Thanks! Macpaul Lin