LS1043A, PCIe Link up query

[logeshs]

Hi,

In LS1043A, PCIe Gen2 interface is connected between LS1043A and Trident 2+ Broadcom Switch. For Trident 2+ switch all the clocks has to be configured only in Linux. Only after all the clocks for Trident 2+ are configured, Reset for Trident 2+ is released. Hence Trident 2+ Switch is released from reset literally after 5 MINUTES of processor reset. 

So we need to establish the PCIe link only after the switch is released from reset (that is 5mins). In this procedure, please suggest do we have any issue in establishing PCIe link between LS1043A and Trident 2+ switch.

Also suggest us in our case does the PCIe link will be established automatically or do we need to take any precautions or do we need to follow any particular procedure?

Thanks.

[ryanjoy]

Does anyone know if a solution was found? I have the same issue and need to establish the PCIe link long after Linux has booted. I have thus far been unable to find the correct reset/relink control bit(s) to write that will cause the LS1043 to establish a link after the endpoint has been powered up.

[ryanjoy]

For us, the solution was to toggle the Soft Reset bit in [PEXLDBG]. That will cause link training to restart.

[r8070z]

Have a great day,

It is not clear if the Broadcom PCIe port is ready for configuration when the Linux driver tries to configure it at start-up. It looks like it is not ready. I.e. Linux fails to configure it in time and you get error message. Later it will not be initialized automatically. The PCI express supports hot-plug (with corresponding software support) but it is not your case. I think it is better to ask Broadcom support for solution. May be bootloader can configure clocks required for the Broadcom PCIe port and after load Linux kernel.

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