Am Freitag, dem 17.09.2021 um 09:28 +0200 schrieb Heiko Thiery: > Hi Frieder, > > Am Mi., 15. Sept. 2021 um 14:09 Uhr schrieb Frieder Schrempf > <frieder.schrempf@xxxxxxxxxx>: > > > > On 15.09.21 14:05, Michael Walle wrote: > > > Am 2021-09-15 14:03, schrieb Heiko Thiery: > > > > The buck2 output of the PMIC is the VDD core voltage of the cpu. > > > > Switching off this will poweroff the CPU. Add the 'regulator-always-on' > > > > property to avoid this. > > > > > > Mh, have this ever worked? Is there a commit which introduced a regression? > > > > Yes, this did work before, even without 'regulator-always-on'. I > > currently don't understand why this is needed. The regulator is > > referenced in the CPU nodes as 'cpu-supply'. This should be enough to > > not disable it as long as the CPU is up. > > I rechecked that with 5.11, 5.10 and 5.9 and I see on all of them the > same issue: > > [ 31.716031] vdd-5v: disabling > [ 31.719032] rst-usb-eth2: disabling > [ 31.722553] buck2: disabling > > While on that I tried to compare with other boards and see that they > also have the cpu-voltage marked as "regulator-always-on". The only > exception in dts/freescale is in imx8mq-librem5-devkit.dts [1] that > has not set this property. > > I agree with you and don't understand why this is happening. Has > anyone else an explanation? > > [1] https://elixir.bootlin.com/linux/latest/source/arch/arm64/boot/dts/freescale/imx8mq-librem5-devkit.dts#L319 > Maybe your kernel config is missing the cpufreq driver, so you don't have a consumer of the regulator? Marking the regulator as always-on seems like the right thing to do, you don't want to depend on a consumer showing up to make sure that your CPU voltage isn't cut... Regards, Lucas
