HDD softreset failed issue on TK1

HDD: SEAGATE 500gb +5v 1.0A
SW version: R21.4

“ata1: softreset failed” happpened on some of our tk1 platform,the log details:
[ 7.218917] ALSA device list:
[ 7.221964] #0: HDA NVIDIA Tegra at 0x70038000 irq 113
[ 14.920410] ata1: softreset failed (1st FIS failed)
[ 20.433410] ata1: link is slow to respond, please be patient (ready=0)
[ 24.927407] ata1: softreset failed (device not ready)
[ 59.932404] ata1: softreset failed (1st FIS failed)
[ 59.937304] ata1: limiting SATA link speed to 1.5 Gbps
[ 65.143412] ata1: softreset failed (device not ready)
[ 65.148484] ata1: reset failed, giving up
if disconnect the power cable for more then 13 mins,it happens 100%
we have no idea about how to fix it,though
1)we are trying to slow down the speed as gen1,but how ?
2)can anyone give advises on what should be payed attention to when designing our product

Hi, there is routing layout guideline in OEM DG, did you follow that to do high speed line design? All your custom board are same design but only some of them failed on HDD, right? Did you try more HDD device to crosscheck? Is it possible interfered by other high speed signals? Also you can probe the signals with scope to check signal quality.

HI,Trumany:
thanks for your reply. so far,we got one like this while more then 20 ohters are ok;it’s the same when we try another HDD,and we will check the signals quality later.Any advises on setting speed to gen1 ?

thank you.