Re: [PATCH v3 1/4] remoteproc: core: Move cdev add before device add

Greg KH
2021-06-15T04:56:19Z

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?