Re: [PATCH 0/3] rust: miscdevice: Add additional data to MiscDeviceRegistration

[Christian Schrefl <chrisi.schrefl@gmail.com>]

On 20.01.25 6:46 AM, Greg Kroah-Hartman wrote:
> On Sun, Jan 19, 2025 at 11:11:12PM +0100, Christian Schrefl wrote:
>> This set is based on Greg's driver-core-next tree.
>>
>> Currently there is no good way to pass arbitrary data from the driver to
>> a miscdevice or to share data between individual handles to a miscdevice in rust.
> 
> Why would you want to do this?  A misc device instance should be "self
> contained" with the needed stuff to make it work.
> 
> Do you have an example of where this is needed as I can't figure out the
> goal here, sorry.

The main reason for needing this was that I could not figure out how to otherwise
use a Devres from the platfrom driver probe in the implementation of the miscdevice.
The reason to add this to MiscDeviceRegistration is to avoid race-conditions between
the fops and driver registration/deregistration.
(See the commit description of patch 2/3)

If there is a better or more intended way to achieve that please let me know.

> 
> thanks,
> 
> greg k-h