nand read / write speed is too slow in uboot.
The following results reasonable?
NAND erase.part: device 0 offset 0x0, size 0x6000000
Skipping bad block at 0x00c80000
Skipping bad block at 0x00ca0000
Skipping bad block at 0x03c00000
Skipping bad block at 0x03c20000
Skipping bad block at 0x03c40000
Skipping bad block at 0x03c60000
Skipping bad block at 0x03c80000
Skipping bad block at 0x03ca0000
Skipping bad block at 0x03cc0000
Skipping bad block at 0x03ce0000
Skipping bad block at 0x03d00000
Skipping bad block at 0x03d20000
Skipping bad block at 0x03d40000
Skipping bad block at 0x03d60000
Skipping bad block at 0x03d80000
Skipping bad block at 0x03da0000
Skipping bad block at 0x03dc0000
Skipping bad block at 0x03de0000
Skipping bad block at 0x03e00000
Skipping bad block at 0x03e20000
Skipping bad block at 0x03e40000
Skipping bad block at 0x03e60000
Skipping bad block at 0x03e80000
Skipping bad block at 0x03ea0000
Skipping bad block at 0x03ec0000
Skipping bad block at 0x03ee0000
Skipping bad block at 0x03f00000
Skipping bad block at 0x03f20000
Skipping bad block at 0x03f40000
Skipping bad block at 0x03f60000
Skipping bad block at 0x03f80000
Skipping bad block at 0x03fa0000
Skipping bad block at 0x03fc0000
Skipping bad block at 0x03fe0000
Skipping bad block at 0x04000000
Skipping bad block at 0x04700000
Skipping bad block at 0x04720000
Skipping bad block at 0x04740000
Skipping bad block at 0x04760000
Skipping bad block at 0x04780000
Skipping bad block at 0x047a0000
Skipping bad block at 0x047c0000
Skipping bad block at 0x047e0000
Skipping bad block at 0x04800000
Skipping bad block at 0x04820000
Skipping bad block at 0x04840000
Skipping bad block at 0x04860000
Skipping bad block at 0x04880000
Skipping bad block at 0x048a0000
Skipping bad block at 0x048c0000
Skipping bad block at 0x048e0000
Skipping bad block at 0x04900000
Skipping bad block at 0x04920000
Skipping bad block at 0x04940000
Skipping bad block at 0x04960000
Skipping bad block at 0x04980000
Skipping bad block at 0x049a0000
Skipping bad block at 0x049c0000
Skipping bad block at 0x049e0000
Skipping bad block at 0x04a00000
Skipping bad block at 0x04a20000
Skipping bad block at 0x04a40000
Skipping bad block at 0x04a60000
Skipping bad block at 0x04a80000
Skipping bad block at 0x04aa0000
Skipping bad block at 0x04ac0000
Skipping bad block at 0x04ae0000
Skipping bad block at 0x04b00000
Skipping bad block at 0x04b20000
Skipping bad block at 0x04b40000
Skipping bad block at 0x04b60000
Skipping bad block at 0x04b80000
Skipping bad block at 0x04ba0000
Skipping bad block at 0x04bc0000
Skipping bad block at 0x04be0000
Skipping bad block at 0x04c00000
Skipping bad block at 0x04c20000
Skipping bad block at 0x04c40000
Skipping bad block at 0x04c60000
Skipping bad block at 0x04c80000
Skipping bad block at 0x04ca0000
Skipping bad block at 0x04cc0000
Skipping bad block at 0x04ce0000
Skipping bad block at 0x04d00000
Skipping bad block at 0x04d20000
Skipping bad block at 0x04d40000
Skipping bad block at 0x04d60000
Skipping bad block at 0x04d80000
Skipping bad block at 0x04da0000
Skipping bad block at 0x04dc0000
Skipping bad block at 0x04de0000
Skipping bad block at 0x04e00000
Skipping bad block at 0x04e20000
Skipping bad block at 0x04e40000
Skipping bad block at 0x04e60000
Skipping bad block at 0x04e80000
Skipping bad block at 0x04ea0000
Skipping bad block at 0x04ec0000
Skipping bad block at 0x04ee0000
Skipping bad block at 0x04f00000
Skipping bad block at 0x04f20000
Skipping bad block at 0x04f40000
Skipping bad block at 0x04f60000
Skipping bad block at 0x04f80000
Skipping bad block at 0x04fa0000
Skipping bad block at 0x04fc0000
Skipping bad block at 0x04fe0000
Skipping bad block at 0x05000000
Skipping bad block at 0x05020000
Skipping bad block at 0x05040000
Skipping bad block at 0x05060000
Skipping bad block at 0x05080000
Skipping bad block at 0x050a0000
Skipping bad block at 0x050c0000
Skipping bad block at 0x050e0000
Skipping bad block at 0x05100000
Skipping bad block at 0x05120000
Skipping bad block at 0x05140000
Skipping bad block at 0x05160000
Skipping bad block at 0x05180000
Skipping bad block at 0x051a0000
Skipping bad block at 0x051c0000
Skipping bad block at 0x051e0000
Skipping bad block at 0x05200000
Skipping bad block at 0x05220000
Skipping bad block at 0x05240000
Skipping bad block at 0x05260000
Skipping bad block at 0x05280000
Skipping bad block at 0x052a0000
Skipping bad block at 0x052c0000
Skipping bad block at 0x052e0000
Skipping bad block at 0x05300000
Skipping bad block at 0x05320000
Skipping bad block at 0x05340000
Skipping bad block at 0x05360000
Skipping bad block at 0x05380000
Skipping bad block at 0x053a0000
Skipping bad block at 0x053c0000
Skipping bad block at 0x053e0000
Skipping bad block at 0x05400000
Skipping bad block at 0x05420000
Skipping bad block at 0x05440000
Skipping bad block at 0x05460000
Skipping bad block at 0x05480000
Skipping bad block at 0x054a0000
Skipping bad block at 0x054c0000
Skipping bad block at 0x054e0000
Skipping bad block at 0x05500000
Skipping bad block at 0x05520000
Skipping bad block at 0x05540000
Skipping bad block at 0x05560000
Skipping bad block at 0x05580000
Skipping bad block at 0x055a0000
Skipping bad block at 0x055c0000
Skipping bad block at 0x055e0000
Skipping bad block at 0x05600000
Skipping bad block at 0x05620000
Skipping bad block at 0x05640000
Skipping bad block at 0x05660000
Skipping bad block at 0x05680000
Skipping bad block at 0x056a0000
Skipping bad block at 0x056c0000
Skipping bad block at 0x056e0000
Skipping bad block at 0x05700000
Skipping bad block at 0x05720000
Skipping bad block at 0x05740000
Skipping bad block at 0x05760000
Skipping bad block at 0x05780000
Skipping bad block at 0x057a0000
Skipping bad block at 0x057c0000
Skipping bad block at 0x057e0000
Skipping bad block at 0x05800000
Skipping bad block at 0x05820000
Skipping bad block at 0x05840000
Skipping bad block at 0x05860000
Skipping bad block at 0x05880000
Skipping bad block at 0x058a0000
Skipping bad block at 0x058c0000
Skipping bad block at 0x058e0000
Skipping bad block at 0x05900000
Skipping bad block at 0x05920000
Skipping bad block at 0x05940000
Skipping bad block at 0x05960000
Skipping bad block at 0x05980000
Skipping bad block at 0x059a0000
Skipping bad block at 0x059c0000
Skipping bad block at 0x059e0000
Skipping bad block at 0x05a00000
Skipping bad block at 0x05a20000
Skipping bad block at 0x05a40000
Skipping bad block at 0x05a60000
Skipping bad block at 0x05a80000
Skipping bad block at 0x05aa0000
Erasing at 0x5fe0000 -- 100% complete.
OK
2 second
NAND write: device 0 offset 0x0, size 0x293f554
Skip bad block 0x00c80000
Skip bad block 0x00ca0000
43251028 bytes written: OK
48 second ( cmd : nand write.i )
NAND read: device 0 offset 0x0, size 0x293f554
Skipping bad block 0x00c80000
Skipping bad block 0x00ca0000
43251028 bytes read: OK
54 second ( cmd : nand read.i )
My environment:
u-boot-2014.07-g7e537bf
nand flash : MT29F2G08AB
U-Boot# nand info
Device 0: nand0, sector size 128 KiB
Page size 2048 b
OOB size 64 b
Erase size 131072 b
