RCs are in fact the time and place for all sorts of bug fixes, not just those which concern code added by that particular merge window. However, in this case it seems the kexec fix was deemed inappropriate due to its size, risk of introducing other bugs or simply because it did not or would not get enough testing before the release.
Originally Posted by TheBlackCat
Or at least that's my guess, since the LKML thread itself isn't particularly enlightening and might give the wrong impression. Have a look at the actual patch and Dave's 2nd reply after the merge request, where he says that approach might not be the best anyway.
kexec. Which basically loads a new kernel into memory and executes it. The whole idea is so somewhat nutty as lots of devices have dma in progress. So the fix was to disable certain GPU features that use dma early in the driver init process so that any previously active operations from before kexec will hopefully be stopped before the driver gets a chance to set up the hardware again.
Originally Posted by sandy8925