Am Freitag, 11. Oktober 2024, 11:04:38 CEST schrieb Dragan Simic: > Hello Jonas, > > On 2024-10-11 10:52, Jonas Karlman wrote: > > On 2024-10-10 12:19, Dragan Simic wrote: > >> Until the TSADC, thermal zones, thermal trips and cooling maps are > >> defined > >> in the RK3308 SoC dtsi, none of the CPU OPPs except the slowest one > >> may be > >> enabled under any circumstances. Allowing the DVFS to scale the CPU > >> cores > >> up without even just the critical CPU thermal trip in place can rather > >> easily > >> result in thermal runaways and damaged SoCs, which is bad. > >> > >> Thus, leave only the lowest available CPU OPP enabled for now. > > > > This feel like a very aggressive limitation, to only allow the > > opp-suspend rate, that is not even used under normal load. > > > > I let my Rock Pi S board with a RK3308B variant run "stress -c 8" for > > around 10 hours and the reported temp only reach around 50-55 deg c, > > ambient temp around 20 deg c and board laying flat on a table without > > any enclosure or heat sink. > > > > This was running with performance as scaling_governor and cpu running > > the 1008000 opp. > > Thanks for testing all that! That's very low CPU temperature under > stress testing indeed. Maybe the cooling gets worse and the CPU > temperature goes higher if the board is installed into some small > enclosure with no natural or forced airflow? > > > Most RK3308 variants datasheets list 1.3 GHz as max rate for CPU, > > the K-variant lists 1.2 GHz, and the -S-variants seem to have both > > reduced voltage and max rate. > > > > The OPPs for this SoC already limits max rate to 1 GHz and is more than > > likely good enough to not reach the max temperature of 115-125 deg c as > > rated in datasheets and vendor DTs. > > > > Adding the tsadc and trips (same/similar as px30) will probably allow > > us > > to add/use the "missing" 1.2 and 1.3 GHz OPPs. > > With these insights, I agree that the patch might have been a bit > too extreme, but it also promotes good practices when it comes to > upstreaming. The general rule is not to add CPU or GPU OPPs with > no proper thermal configuration already in place. > > The patch has already been merged, and as I already noted, [1] I'll > try to implement, test and submit the proper thermal configuration > ASAP. It's up Heiko to decide whether to drop this patch or not. Hmm, interesting question ;-) . Dropping the patch is of course still possible and so far we haven't actually seen anyone with real-world problems. And with Jonas' stress test, it does look like nobody will in the (hopefully short) time till we have thermal management. @Dragan, if you're in favor of that I'll drop the patch. Heiko > > [1] > https://lore.kernel.org/linux-rockchip/df92710498f66bcb4580cb2cd1573fb2@xxxxxxxxxxx/ > > >> Fixes: 6913c45239fd ("arm64: dts: rockchip: Add core dts for RK3308 > >> SOC") > >> Cc: stable@xxxxxxxxxxxxxxx > >> Signed-off-by: Dragan Simic <dsimic@xxxxxxxxxxx> > >> --- > >> arch/arm64/boot/dts/rockchip/rk3308.dtsi | 3 +++ > >> 1 file changed, 3 insertions(+) > >> > >> diff --git a/arch/arm64/boot/dts/rockchip/rk3308.dtsi > >> b/arch/arm64/boot/dts/rockchip/rk3308.dtsi > >> index 31c25de2d689..a7698e1f6b9e 100644 > >> --- a/arch/arm64/boot/dts/rockchip/rk3308.dtsi > >> +++ b/arch/arm64/boot/dts/rockchip/rk3308.dtsi > >> @@ -120,16 +120,19 @@ opp-600000000 { > >> opp-hz = /bits/ 64 <600000000>; > >> opp-microvolt = <950000 950000 1340000>; > >> clock-latency-ns = <40000>; > >> + status = "disabled"; > >> }; > >> opp-816000000 { > >> opp-hz = /bits/ 64 <816000000>; > >> opp-microvolt = <1025000 1025000 1340000>; > >> clock-latency-ns = <40000>; > >> + status = "disabled"; > >> }; > >> opp-1008000000 { > >> opp-hz = /bits/ 64 <1008000000>; > >> opp-microvolt = <1125000 1125000 1340000>; > >> clock-latency-ns = <40000>; > >> + status = "disabled"; > >> }; > >> }; >
