回复 4# qladxk2008
OK,L0This is the normal operational state.
‰ LinkUp = 1b (status is set true).
• On receipt of an STP or SDP Symbol, the idle_to_rlock_transitioned variable is reset to 0b
‰ Next state is Recovery if directed to change speed (directed_speed_change = 1b) by a higher
5 layer when both sides support greater than 2.5 GT/s speeds and the Link is in DL_Active state.The changed_speed_recovery bit is reset to 0b.
Next state is Recovery if directed to this state. If Electrical Idle is detected/inferred on all Lanes
25 without receiving an EIOS on any Lane, the Port may transition to the Recovery state or mayremain in L0. In the event that the Port is in L0 and the Electrical Idle condition occurs withoutreceiving an EIOS, errors may occur and the Port may be directed to transition to Recovery.
• Note: As described in Section 4.2.4.2, an Electrical Idle condition may be inferred on allLanes under any one of the following conditions: (i) absence of an Update_FC DLLP in
30 any 128 μs window, (ii) absence of a Skip Ordered Set in any of the configured Lanes in any128 μs window, or (iii) absence of either Update_FC DLLP or a Skip Ordered Set in any ofthe configured Lanes in any 128 μs window.
• Note: “if directed” applies to a Port that is instructed by a higher Layer to transition toRecovery including the Retrain Link bit in the Link Control register being set.
35 • Note: The Transmitter may complete any TLP or DLLP in progress.
感觉这一段可能是原因,虽然进入了L0状态一会,但是状态一直在跳转,很大可能是检测到了 Electrical idle状态。现在就是不知道这个状态产生的原因。
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