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?
