在 2017-10-31 15:57，Jagan Teki 写道：
On Tue, Oct 31, 2017 at 5:06 AM, Icenowy Zheng icenowy@aosc.io wrote:
Some H5 boards are designed to start at 1.1V CPUx voltage (e.g. Nano Pi NEO2), which may not work properly at 1008MHz if the chip's quality is not so good.
Lower the default CPUx frequency of H5 to 816MHz.
Signed-off-by: Icenowy Zheng icenowy@aosc.io
arch/arm/mach-sunxi/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/arm/mach-sunxi/Kconfig b/arch/arm/mach-sunxi/Kconfig index 09cfec6f57..1fededd0a3 100644 --- a/arch/arm/mach-sunxi/Kconfig +++ b/arch/arm/mach-sunxi/Kconfig @@ -397,9 +397,9 @@ config SYS_CLK_FREQ default 1008000000 if MACH_SUN5I default 1008000000 if MACH_SUN6I default 912000000 if MACH_SUN7I
default 816000000 if MACH_SUN50I || MACH_SUN50I_H5 default 1008000000 if MACH_SUN8IEven orangepi pc2 has 1.1v after power-on and it's work fine [1] did you find an issue with neo2?
Yes, the boot process randomly hang at SPL stage -- but when it enters ATF it will run smoothly as the ATF will re-configure CPUx frequency to 816MHz.
According to the official operating point table [2], 1008MHz is bound to 1.2V, and 816MHz is bound to 1.1V.
Allwinner chips usually have not-so-good quality control to reach the low price, and different chips may work differently in situations that is beyond the official the OPP table.
[2] https://github.com/OrangePiLibra/OrangePi_H5SDK/blob/master/external/sys_con...
[1] http://linux-sunxi.org/Xunlong_Orange_Pi_PC_2#CPU_clock_speed_limit
thanks!