Messages in this thread | | | Subject | Re: [RFC 1/1] clk: Add notifier support in clk_prepare_enable/clk_disable_unprepare | From | Bill Huang <> | Date | Thu, 14 Mar 2013 02:28:07 -0700 |
| |
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.
| |