On 2012-08-04 20:53:00 (+0530), Sannu K [off-list ref] wrote:

I had a doubt for long regarding hibernation. It takes a very long
time to resume from hibernation in Linux compared to windows. 

I don't actually have a windows machine to compare. It's quite possible
that this is true, but I can't say why it'd be the case.

Why should all the drivers be started again? Just we can load
the disk driver and some essential part of the kernel, disk driver (or
only few drivers necessary for reading the hibernate image) and use
the drivers stored in the disk (from hibernation image) for rest of
the devices. 

When resuming from hibernation all devices were powered down. The kernel
needs to run through all of the initialisation code again. It needs to
upload firmware, set configuration registers, ...

Regards,
Kristof