From mboxrd@z Thu Jan 1 00:00:00 1970 From: michal.simek@xilinx.com (Michal Simek) Date: Mon, 14 Aug 2017 16:35:34 +0200 Subject: [PATCH 1/3] dt: xilinx: zynqmp: Add bindings for PM firmware In-Reply-To: References: <8c27b7eec6cc00d37dfe9b3998212ce9c9c27a31.1501854302.git.michal.simek@xilinx.com> <20170810191056.ur5b3zdrcgmb6sim@rob-hp-laptop> <4e5d9f8c-9e87-bdcd-388a-aab3c32415e8@xilinx.com> <20170811135453.GU12347@toto> <5d2e3a5e-6060-ff13-a065-c4b6be37e4c9@xilinx.com> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 14.8.2017 16:03, Rob Herring wrote: > On Mon, Aug 14, 2017 at 8:47 AM, Michal Simek wrote: >> On 11.8.2017 15:54, Edgar E. Iglesias wrote: >>> On Fri, Aug 11, 2017 at 02:58:03PM +0200, Michal Simek wrote: >>>> Hi Rob, +Edgar, >>>> >>>> On 10.8.2017 21:10, Rob Herring wrote: >>>>> On Fri, Aug 04, 2017 at 03:45:30PM +0200, Michal Simek wrote: >>>>>> From: Soren Brinkmann >>>>>> >>>>>> Document the DT bindings for the Zynq UltraScale+ PM Firmware. > > [...] > >>>>>> + - method: The method of calling the PM-API firmware layer. >>>>>> + Permitted values are: >>>>>> + - "smc" : To be used in configurations without a hypervisor >>>>>> + - "hvc" : To be used when hypervisor is present >>>>> >>>>> Do you really use both? >>>>> >>>> >>>> SMCs definitely yes. >>>> >>>> Interface was designed in that way and I don't know if people are using >>>> it or not. >>>> >>>> Not sure if Xen is blocking SMCs. I know we have discussed it but not >>>> sure if this is enabled by default or only for certain configurations. >>>> Also not sure if xen contains handler for hvc. >>>> Edgar: Do you know? >>> >>> We have patches for Xen that implement a power-management mediator. >>> That implementation handles PM calls over both SMC and HVC insns. >>> Patches are on the Xen mailing list. >>> >>> Other hypervisors may work differently. >>> >>> I think we should support both but I don't have a strong opinion on it. >> >> Rob: Are you ok with having it there? > > Yes. Ok. Let me send v2 then. Thanks, Michal