On Fri, May 15, 2015 at 11:03:35AM +0200, Tomeu Vizoso wrote: > I have been looking and asking around, and seems like we should > actually leave FIQs enabled when the tick is frozen and only disable > them within enter_freeze. > > My understanding is that FIQ handlers are extremely limited in what > they can do, with the main use being NMI-like functionality. There are > a handful of other FIQ handlers in mainline, but they don't call into > any other kernel code and limit themselves to doing some basic I/O. > > The only reason why they should be disabled in enter_freeze is that > the context of the CPU that is going to a lower power state could > become corrupted if a FIQ gets fired during a save or restore > operation.
Right, that makes total sense. (And yes, FIQ handlers are very limited in what they're allowed to do, since they can't take any locks without the potential for deadlock.) -- FTTC broadband for 0.8mile line: currently at 10.5Mbps down 400kbps up according to speedtest.net. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
