On 15.06.2023 19:35, Stephen Boyd wrote: > Quoting Konrad Dybcio (2023-06-15 00:52:07) >> On 15.06.2023 02:49, Stephen Boyd wrote: >>> Quoting Konrad Dybcio (2023-06-14 11:04:19) >>>> This series reshuffles things around, moving the management of SMD RPM >>>> bus clocks to the interconnect framework where they belong. This helps >>>> us solve a couple of issues: >>>> >>>> 1. We can work towards unused clk cleanup of RPMCC without worrying >>>> about it killing some NoC bus, resulting in the SoC dying. >>>> Deasserting actually unused RPM clocks (among other things) will >>>> let us achieve "true SoC-wide power collapse states", also known as >>>> VDD_LOW and VDD_MIN. >>>> >>>> 2. We no longer have to keep tons of quirky bus clock ifs in the icc >>>> driver. You either have a RPM clock and call "rpm set rate" or you >>>> have a single non-RPM clock (like AHB_CLK_SRC) or you don't have any. >>>> >>>> 3. There's less overhead - instead of going through layers and layers of >>>> the CCF, ratesetting comes down to calling max() and sending a single >>>> RPM message. ICC is very very dynamic so that's a big plus. >>>> >>>> The clocks still need to be vaguely described in the clk-smd-rpm driver, >>>> as it gives them an initial kickoff, before actually telling RPM to >>>> enable DVFS scaling. After RPM receives that command, all clocks that >>>> have not been assigned a rate are considered unused and are shut down >>>> in hardware, leading to the same issue as described in point 1. >>> >>> Why can't we move the enable of DVFS scaling call to the interconnect >>> driver as well? We want the clk driver to not reference the interconnect >>> resources at all. >> That would result in no rpmcc ratesetting on platforms without a functional >> interconnect driver. The DVFS call concerns both bus and !bus clocks. >> > > That's the intent. Probe the interconnect driver to get bus clk rate > setting. > > What are the !bus clocks managed by RPM? Depending on the platform, that includes IPA, GPU, OCMEM, RF.. everything that's not been separated out in patch 18. Konrad
