reserved-memory {

　　#address-cells = <2>;

　　#size-cells = <2>;

　　ranges;

　　 reserved: buffer@0 {

　　　　compatible = "shared-dma-pool";

　　　　reusable;

　　　　reg = <0x0 0x70000000 0x0 0x10000000>;

　　　　linux,cma-default; };

};

 

dts中配置了预留的memery

[ 0.000000] Reserved memory: created CMA memory pool at 0x0000000060000000, size 512 MiB
[ 0.000000] OF: reserved mem: initialized node rknpu, compatible id shared-dma-pool
[ 0.000000] Reserved memory: created CMA memory pool at 0x0000000010000000, size 8 MiB
[ 0.000000] OF: reserved mem: initialized node linux,cma, compatible id shared-dma-pool

所以导致2G的DDR实际上只有1.3G

去掉后解决问题