Messages in this thread | | | From | Andy Lutomirski <> | Date | Tue, 30 Aug 2016 13:21:20 -0700 | Subject | Re: [PATCH 3/3] nvme: Enable autonomous power state transitions |
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On Mon, Aug 29, 2016 at 4:16 PM, Andy Lutomirski <luto@amacapital.net> wrote: > On Aug 29, 2016 8:07 AM, "J Freyensee" > <james_p_freyensee@linux.intel.com> wrote: >> >> On Mon, 2016-08-29 at 02:25 -0700, Andy Lutomirski wrote: >> > NVME devices can advertise multiple power states. These states can >> > be either "operational" (the device is fully functional but possibly >> > slow) or "non-operational" (the device is asleep until woken up). >> > Some devices can automatically enter a non-operational state when >> > idle for a specified amount of time and then automatically wake back >> > up when needed. >> >
>> >> > + /* >> > + * By default, allow up to 25ms of APST-induced >> > latency. This will >> > + * have no effect on non-APST supporting controllers (i.e. >> > any >> > + * controller with APSTA == 0). >> > + */ >> > + ctrl->apst_max_latency_ns = 25000000; >> >> Is it possible to make that a #define please? > > I'll make it a module parameter as Keith suggested.
One question, though: should we call this and the sysfs parameter apst_max_latency or should it be more generically power_save_max_latency? The idea is that we might want to support non-automonous transitions some day or even runtime D3. Or maybe those should be separately configured if used.
--Andy
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