Hi David, On 05/30/2018 11:57 PM, David Collins wrote: > Hello Rajendra, > > On 05/30/2018 03:14 AM, Rajendra Nayak wrote: >> On 05/30/2018 02:47 PM, Ulf Hansson wrote: >>> On 25 May 2018 at 12:01, Rajendra Nayak <rnayak@xxxxxxxxxxxxxx> wrote: > ... >>>> + pm_genpd_init(&rpmpds[i]->pd, NULL, true); >>> >>> Question: Is there no hierarchical topology of the PM domains. No >>> genpd subdomains? >> >> The hierarchy if any is all handled by the remote core (RPM in this case). >> For Linux its just a flat view. > > There is one special case that we'll need to handle somehow. The APPS > vlvl request for VDD_MX needs to be greater than or equal to the vlvl > request for VDD_CX. Can you please add the necessary code to achieve > this? RPMh hardware doesn't handle this hardware requirement due to > concerns about modem use case latency. Sure, I'll take a look at it. > > Please note that this is handled in a somewhat hacky manner [1] with the > downstream rpmh-regulator driver by specifying VDD_MX as the parent of > VDD_CX and VDD_MX_AO as the parent of VDD_CX_AO with a dropout voltage of > -1. That way, enabling CX causes MX to be enabled and voltage level > requests are propagated from CX to MX (the -1 is ignored because it is > rounded up within the sparse vlvl numbering space). I can't see how else to handle this but with a fake parent/child relation, which also means we might need support to propagate performance states for power domains up the parents, which I think was initially supported but later dropped since we thought this wasn't needed for now. We might need to take a re-look at it to support this usecase. thanks, Rajendra -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
