Asynchronous Device Shutdown Doesn't Make It For Linux 6.12

Patches for wiring up async device shutdown within the Linux kernel were queued via the driver core branch for the in-development Linux 6.12 kernel. However, at the last minute these asynchronous device shutdown patches were reverted so that they can be reworked and hopefully land for the Linux v6.13 kernel in the new year.

Going on for months have been various efforts for async device shutdown support for the Linux kernel so that device drivers/hardware can opt-in to handling shutting down of devices asynchronously. This is intended to deal with slow shutdowns/reboots when having many devices attached like lots of storage devices. But last minute issues have led to these patches being postponed from their planned introduction in Linux v6.12.

At an extreme this opt-in asynchronous device shutdown support allowed a server that had taken 11 minutes to reboot to now do so in 55 seconds when having lots of NVMe drives attached. After reverting the async shutdown patches, Greg Kroah-Hartman sent out the driver core changes for Linux 6.12 and noted they'll hopefully be reworked for v6.13 next year. As for what's in the driver core changes now, it's mostly small clean-ups and fixes.