Re: [PATCH 2/2] Fix console handling during suspend/resume

Alan Stern
2006-06-15T17:04:41Z

On Thu, 15 Jun 2006, Linus Torvalds wrote:

> In order for this to actually _work_, you need to have
>
> device_save_state();
> .. calls down to each device, saving their ..
> .. state BUT NOT SUSPENDING THEM! ..
> .. This phase can return an error, and can do ..
> .. things like memory allocations. ..
>
> .. If an error happens here, we just return. We ..
> .. do NOT "restore" any state, because there IS ..
> .. NO STATE TO RESTORE - we've not actually ..
> .. _changed_ anything ..
>
> .. In other words, for a regular PCI device ..
> .. this function does "pci_save_state()". Not ..
> .. _anything_ else! ..
>
> save_image_to_disk();
> .. NONE OF THE DEVICES ARE SUSPENDED! So all the ..
> .. idiotic crap about trying to keep the "suspend ..
> .. device" alive would be the obvious crap it is! ..

How can you create a consistent memory image if devices are doing DMA into
memory while the snapshot is in progress?

Alan Stern