am5728连接硬盘问题

5728上电连不上硬盘，反复出现下面的信息：

[ 74.797737] ata1: SATA link down (SStatus 1 SControl 310)
[ 74.803185] ata1: EH complete
[ 74.812154] ata1: exception Emask 0x10 SAct 0x0 SErr 0x4040000 action 0xe frozen
[ 74.819649] ata1: irq_stat 0x00000040, connection status changed
[ 74.825697] ata1: SError: { CommWake DevExch }
[ 74.830377] ata1: limiting SATA link speed to 1.5 Gbps
[ 74.835541] ata1: hard resetting link

能给个检查的思路，谢谢！