在 2022/5/13 16:15, Maxime Ripard 写道:
On Fri, May 13, 2022 at 03:48:50PM +0800, qianfan wrote:
在 2022/5/13 15:38, Maxime Ripard 写道:
Hi,
On Thu, May 12, 2022 at 03:18:58PM +0800, qianfanguijin@xxxxxxx wrote:
From: qianfan Zhao <qianfanguijin@xxxxxxx>
sun8i-r40 actived cpufreq feature now, let's add "cpu-supply" node on
board.
Signed-off-by: qianfan Zhao <qianfanguijin@xxxxxxx>
---
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.
That's not what I meant to say. Those two patches are great separated.
You can invert them though.
haha, invert them, so interesting. good idea.
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.
This probably won't be the case whenever someone starts a new design,
and then they'll face random crashes for no apparent reason, and waste a
lot of time in the process.
Whereas the alternative is that you would be missing some OPPs,
something that is fairly easy to figure out.
How about remove the OPPs which greate that 1.08G in sun8i-r40.dtsi,
If some boards want to run at a higher frequency, can add them byself
in the board's file.
Maxime
