TX2i ECC ON/OFF Memory available size

We found TX2i available memory size vary base on ECC ON or OFF.

When ECC is ON, available memory size is 7159808K.

[    0.000000] Memory: 6944328K/7159808K available (11352K kernel code, 1785K rwdata, 5776K rodata, 1152K init, 720K bss, 149944K reserved, 65536K cma-reserved)
[    0.000000] Virtual kernel memory layout:
                   vmalloc : 0xffffff8000000000 - 0xffffffbdbfff0000   (   246 GB)
                   vmemmap : 0xffffffbdc0000000 - 0xffffffbfc0000000   (     8 GB maximum)
                             0xffffffbdc2000000 - 0xffffffbdc8da0000   (   109 MB actual)
                   fixed   : 0xffffffbffa7fd000 - 0xffffffbffac00000   (  4108 KB)
                   PCI I/O : 0xffffffbffae00000 - 0xffffffbffbe00000   (    16 MB)
                   modules : 0xffffffbffc000000 - 0xffffffc000000000   (    64 MB)
                   memory  : 0xffffffc000000000 - 0xffffffc1b6800000   (  7016 MB)
                     .init : 0xffffffc00113b000 - 0xffffffc00125b000   (  1152 KB)
                     .text : 0xffffffc000080000 - 0xffffffc00113b000   ( 17132 KB)
                     .data : 0xffffffc00127c000 - 0xffffffc00143a448   (  1786 KB)
[    0.000000] SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=6, Nodes=1

When ECC is OFF, available memory size become 8202240K.

[    0.000000] Memory: 7904220K/8202240K available (11336K kernel code, 1783K rwdata, 5752K rodata, 1152K init, 717K bss, 166948K reserved, 131072K cma-reserved)
[    0.000000] Virtual kernel memory layout:
                   vmalloc : 0xffffff8000000000 - 0xffffffbdbfff0000   (   246 GB)
                   vmemmap : 0xffffffbdc0000000 - 0xffffffbfc0000000   (     8 GB maximum)
                             0xffffffbdc2000000 - 0xffffffbdc9d78000   (   125 MB actual)
                   fixed   : 0xffffffbffa7fd000 - 0xffffffbffac00000   (  4108 KB)
                   PCI I/O : 0xffffffbffae00000 - 0xffffffbffbe00000   (    16 MB)
                   modules : 0xffffffbffc000000 - 0xffffffc000000000   (    64 MB)
                   memory  : 0xffffffc000000000 - 0xffffffc1f5e00000   (  8030 MB)
                     .init : 0xffffffc001131000 - 0xffffffc001251000   (  1152 KB)
                     .text : 0xffffffc000080000 - 0xffffffc001131000   ( 17092 KB)
                     .data : 0xffffffc001272000 - 0xffffffc00142fff8   (  1784 KB)

Why ECC is ON, available memory size become from 8202240K to 7159808K? Is that ECC checking occupy part of RAM space?
If ECC is ON, how can we adjust available memory size to 8202240K?

Hi
It’s know problem. Will have detail information when get confirm from internal designer.

ECC functionality needs parity bits and they reside in DRAM. This causes reduction in available memory size.