On Tue, Mar 17, 2015 at 03:08:52PM +0000, Mark Rutland wrote:
it seems that UEFI accesses during boot might have left the device in an unsuitable state for the kernel. this commit aims at correcting that.
It would be nice to know what that state is. I've been bitten by loaders leaving devices on with DMA active, and it would be nice to know that something like that isn't the case here -- it can be tricky to detect until it's too late.
I was under the impression that UEFI drivers were meant to leave devices in some quiescent state. Sepending on the precise state the HW is left it, this may still be a UEFI bug regardless of whether it's possible for the kernel to fix things up, and if that's the case we should fix the UEFI port regardless of whether we also modify the kernel to handle that state.
Indeed - why is this not handled as an ExitBootServices hook in UEFI?
/ Leif