Re: Solving suspend-level confusion

[Pavel Machek]

Hi!

> > Disks in general are an example (IDE beeing the one that is currently
> > implemented, but we'll probably have to do the same for SATA and SCSI
> > at one point), you want to spin them off (with proper cache flush
> > etc...) when suspending to RAM, while you don't when suspending to
> > disk, as you really don't want them to be spun up again right away to
> > write the suspend image.
> 
> So suspend-to-RAM more or less matches PCI D3hot, and
> suspend-to-DISK matches PCI D3cold.  If those power states
> were passed to the device suspend(), the disk driver could act
> appropriately.  In my observation, D3cold was never passed
> down, it was always D3hot.
> 
> These look to me like "wrong device-level suspend state" cases.

Actually, suspend-to-disk has to suspend all devices *twices*. Once it
wants them in "D0 but DMA/interrupts stopped", and once in "D3cold but
I do not really care power is going to be cut anyway". I do not think
this can be expressed with PCI states.
								Pavel
-- 
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