On Thu, 2013-03-14 at 17:21 +0800, Peter De Schrijver wrote: > On Thu, Mar 14, 2013 at 03:15:11AM +0100, Bill Huang wrote: > > > I don't think deferring will work either, considering the usage of DVFS, > > device voltage is tightly coupled with frequency, when clock rate is > > about to increase, we have to boost voltage first and we can lower the > > voltage after the clock rate has decreased. All the above sequence have > > to be guaranteed or you might crash, so deferring not only make thing > > complicated in controlling the order but also hurt performance. > > But we could use notifiers in clk_prepare/clk_unprepare to set the voltage no? > As clk_prepare/clk_unprepare have to be called before clk_enable or after > clk_disable, the voltage can be raised to a safe level, before the clock > becomes active.
Thanks Peter, actually I'm just about to propose my v2 RFC which add notifier in clk_prepare/clk_unprepare. > > Cheers, > > Peter. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
