On Thursday, May 19, 2011, Alan Stern wrote: > On Thu, 19 May 2011, Davide Ciminaghi wrote: > > > I'm not completely sure about this. What we wanted to do was to avoid > > powering > > down the mmc while it is physically writing data into its internal memory. > > If we force a sync when the power loss warning event warning happens, > > it is very difficult to be able to guarantee that all buffered data will be > > written before power actually dies. So we preferred to follow another > > strategy: > > let the mmc finish any running write operation, and then stop its request > > queue. If power really goes down, then we hope that the file system journal > > will fix things on next boot (yes, some data could get lost, but the fs > > should > > still be mountable). On the other hand, if power resumes, nothing bad > > should > > happen for user space processes. > > You could consider a totally different approach. > > Each platform will have a different set of high-power devices it wants > to turn off when a power-loss warning occurs. So instead of changing > the core PM interface, you could add a new "power_loss" notifier list. > Only the most critical drivers would need to listen for notifications, > and this could be different drivers on different platforms.
Moreover, it would allow not only drivers, but also filesystems (for one example) to get notifications. Thanks, Rafael _______________________________________________ Davinci-linux-open-source mailing list Davinci-linux-open-source@linux.davincidsp.com http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source
