Messages in this thread | | | Date | Fri, 13 May 2022 15:48:50 +0800 | Subject | Re: [PATCH v3 2/2] ARM: dts: sun8i-r40: Add "cpu-supply" node for sun8i-r40 based board | From | qianfan <> |
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在 2022/5/13 15:38, Maxime Ripard 写道: > Hi, > > On Thu, May 12, 2022 at 03:18:58PM +0800, qianfanguijin@163.com wrote: >> From: qianfan Zhao <qianfanguijin@163.com> >> >> sun8i-r40 actived cpufreq feature now, let's add "cpu-supply" node on >> board. >> >> Signed-off-by: qianfan Zhao <qianfanguijin@163.com> >> --- >> arch/arm/boot/dts/sun8i-r40-bananapi-m2-ultra.dts | 4 ++++ >> arch/arm/boot/dts/sun8i-r40-feta40i.dtsi | 4 ++++ >> arch/arm/boot/dts/sun8i-t3-cqa3t-bv3.dts | 4 ++++ >> arch/arm/boot/dts/sun8i-v40-bananapi-m2-berry.dts | 4 ++++ >> 4 files changed, 16 insertions(+) >> >> diff --git a/arch/arm/boot/dts/sun8i-r40-bananapi-m2-ultra.dts b/arch/arm/boot/dts/sun8i-r40-bananapi-m2-ultra.dts >> index a6a1087a0c9b..4f30018ec4a2 100644 >> --- a/arch/arm/boot/dts/sun8i-r40-bananapi-m2-ultra.dts >> +++ b/arch/arm/boot/dts/sun8i-r40-bananapi-m2-ultra.dts >> @@ -113,6 +113,10 @@ &ahci { >> status = "okay"; >> }; >> >> +&cpu0 { >> + cpu-supply = <®_dcdc2>; >> +}; >> + > This will break bisection on those boards. Indeed, you added the OPPs on > the first patch, and if you only apply that patch, the boards in the > second patch will be missing their CPU regulator. The kernel will then > ramp up the frequency to the highest OPP, but will not change the > voltage, resulting in a crash. This is a good point and I will merge those two patch. > > There's a similar issue for all the boards that don't have a regulator > in the first place. > > The way we worked around this for the other SoCs is to have a DTSI with > the OPPs with a frequency higher than what U-Boot boots with (1008MHz?), > and only include that DTSI on boards that have a CPU regulator hooked in. Is this really necessary? It seems like every board based on sun8i-r40 have a cpu regulator. > > Maxime
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