On Mon, Jun 14, 2021 at 07:21:08PM -0700, Siddharth Gupta wrote: > When cdev_add is called after device_add has been called there is no > way for the userspace to know about the addition of a cdev as cdev_add > itself doesn't trigger a uevent notification, or for the kernel to > know about the change to devt. This results in two problems: > - mknod is never called for the cdev and hence no cdev appears on > devtmpfs. > - sysfs links to the new cdev are not established. > > The cdev needs to be added and devt assigned before device_add() is > called in order for the relevant sysfs and devtmpfs entries to be > created and the uevent to be properly populated. So this means no one ever ran this code on a system that used devtmpfs? How was it ever tested?
