did try on 
annoying you have to find extra configs trhrough commits or diffing .config 

4.19-193 raxda
4.19-206 firefly and patched firefly 150balbes-355xx-next
4.19-211 150balbes -35xx didnt find the origin 211 

4.19.219 150balbes 
4.19.219 latest from mirror 4.19
with uboot 3568 1560 ddr bin 1.11 and 1.12 
&lpddr4_params {
	/* freq info, freq_0 is final frequency, unit: MHz */
	freq_0 = <1560>;
	freq_1 = <324>;
	freq_2 = <528>;
	freq_3 = <780>;
};
&lpddr4x_params {
	/* freq info, freq_0 is final frequency, unit: MHz */
	freq_0 = <1560>;
	freq_1 = <324>;
	freq_2 = <528>;
	freq_3 = <780>;
};
and remove 
&dmc {
	system-status-freq = <
		/*system status         freq(KHz)*/
		SYS_STATUS_NORMAL       780000
		SYS_STATUS_REBOOT       1056000
		SYS_STATUS_SUSPEND      324000
		SYS_STATUS_VIDEO_1080P  528000
		SYS_STATUS_BOOST        1056000
		SYS_STATUS_ISP          1056000
		SYS_STATUS_PERFORMANCE  1056000
	>;
};
&dmc_opp_table {
	opp-1056000000 {
		opp-hz = /bits/ 64 <1056000000>;
		opp-microvolt = <900000>;
		opp-microvolt-L0 = <900000>;
		opp-microvolt-L1 = <850000>;
	};
	/delete-node/ opp-1560000000;
};
ow and 
# CONFIG_DEVFREQ_EVENT_ROCKCHIP_NOCP is not set
did keep me a busy a while 
memtest runs nice on bsp  
ddrtest
glmark2 
cpu stress 
etc