Asynchronous Device/Driver Probing For The Linux Kernel
Dmitry Torokhov and other developers are working toward making the driver probe() method asynchronous since the kernel boot process can be stalled by drivers that are slow at probing.
Dmitry put out eight patches on Friday based on the work done by Chrome OS in this area along by another developer who published some patches a few months ago. Dmitry also has an experimental patch for a fully-asynchronous boot process, but it will likely cause problems for most systems although he got a Rockchip-based system booted to user-space in the fully asynchronous manner.
Those wanting more details on this work can see the patch series. Hopefully these patches or other async probing work will make it to the mainline Linux kernel in the near term.