On Saturday, May 14, 2011, Raffaele Recalcati wrote: > On Sat, May 14, 2011 at 8:53 PM, Oliver Neukum <[email protected]> wrote: > > Am Donnerstag, 12. Mai 2011, 21:27:44 schrieb Rafael J. Wysocki: > >> On Thursday, May 12, 2011, Raffaele Recalcati wrote: > >> > What happen normally in runtime pm implementation is that every devices > >> > are switched off and are enabled only when needed. > >> > In our case instead we have a completely functional embedded system and, > >> > when an asyncrhonous event appear, we have only some tens milliseconds > >> > before the actual power failure takes place. > >> > This patchset add a support in order to switch off not vital part of the > >> > system, > >> > in order to allow the board to survive longer. > >> > This allow the possibility to save important data. > >> > >> OK, so first, who decides what parts of the system are vital and what > >> aren't? > > > > If you know that power is failing in a few miliseconds, only stuff that can > > lead to data > > corruption is vital. In that timeframe you can't even flush buffers. > > Remember that if you switch off some peripherals this timeframe > becomes longer, so maybe you have enough time to sync some storage > devices.
However, switching off peripherals _also_ takes time. So, it may be more useful to take care of the stuff leading to data corruption along with the switching off peripherals. Thanks, Rafael _______________________________________________ Davinci-linux-open-source mailing list [email protected] http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source
