RGMII does not work

[allan_yi]

   hello

I Use LS1043+QCA8337 wiht SGMII ,but it does not work, The ping test failed.  so I want  to do loopback test about the bus of serdes,but I can not do the loopback test abou  serders Of lanA ,because the register of bit 3 can not write.could you give me some advices,or tell me how to do the loopback test thanks a lot!

=> mw.l 0x1ea083c 8
=> md.l 0x1ea083c 1
01ea083c: 00000004 ....
=> mw.l 0x1ea083c 5
=> md.l 0x1ea083c 1
01ea083c: 00000005 ....
=> mw.l 0x1ea083c 0xc
=> md.l 0x1ea083c 1
01ea083c: 00000004 ....
=> mw.l 0x1ea083c c
=> md.l 0x1ea083c 1
01ea083c: 00000004

[ufedor]

The "01b - Loopback Mode" corresponds to the bit value 0x10.

[allan_yi]

when I write 8 to this bit ,but it is fail.FYI