[U-Boot] [PATCH] armv8: layerscape platform pcie link up state judgment strongly

York Sun york.sun at nxp.com
Tue Aug 8 16:13:47 UTC 2017


On 08/07/2017 11:56 PM, Xiaowei Bao wrote:
> Hi York,
> 
> I will pay attention to the case of the case in commit message.
> 
> This patch is for some special reset times for longer pcie devices, in this case, the pcie device may on polling compliance state, the RC considers the pcie device is link up, but the pcie device is not link up, only the L0 state is link up state. So add the link up status judgement mechanisms.
> 
> About 100ms timeout, the pcie spec does not specify the link up timeout time, and the link up state is determined by a state machine. The state machine implementation is relatively complex, refer to uboot of other platform pcie link up state to determine the realization of the mechanism, we evaluated a timeout, in detect state consider the pcie device is link down, in L0 state consider the pcie device is link up, within  100ms in other states can be restored to the L0 state considers the pcie device is link up .

Can you put this information to inline comment? It will help us when we 
read the code later.

Thanks.

York


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