On Sat, Aug 4, 2012 at 9:33 PM, Kristof Provost <kristof@xxxxxxxxxx> wrote: > On 2012-08-04 21:15:15 (+0530), Sannu K <sannumail4foss@xxxxxxxxx> wrote: >> Is it possible to determine the reason for more time in hibernation >> compared to windows (or profile the resume time)? If possible I could >> do it in my machine and get some info which may be useful. Some one >> may jump to solve this (or there may be some magic tweak to get a >> better resume time) once it is profiled. >> > Possibly. I haven't looked at the details of the Linux hibernation > subsystem. Take a look at Documentation/power/basic-pm-debugging.txt for > a basic introduction. Sure I will take a look. > >> >> 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, ... >> >> That makes sense. Does that mean during hibernation the state of >> drivers will not be preserved? > > That's correct. > >> Will the driver code be discarded >> without saving in hibernation image (as we are starting the driver >> again while resuming)? > > Again, I'm not an expert, but I see no reason to preserve the driver > state (or perhaps even the rest of the kernel state). I believe the > kernel doesn't even distinguish between a normal boot and a resume from > hibernation until just before it starts userspace. That's a new info I have got :) > > Regards, > Kristof > Thanks, Sannu K _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
