Hi,
I'm trying on looking an issue of I210 pcie adapter driver for a portable device.
Product: I210 AT A3 stepping (PCIE module), firmeware version Rev 1.7, NVM version 3.25.
The I210 moudle is layouted on the portable device. Over the I210 port, there is a TCP connection between the portable device to the remote Linux server for long-term operation.
Occasionally we encounter a loss of communication between our device and the remote Linux server. Once the communication lost, it cannot recover back unless reboot the portable device. While the remote Linux server always worked well with other devices over its network port.
So I looked into I210 driver on the portable device. I dumped the register value of I210 and found the network adapter didn't writeback the DD bit of TX descriptor at the index TDH.
Per my understand, the DD bit of TX descriptor is handled by I210 MC firmware completely and host driver will not touch it, so I don't know what's going on in I210 firmware.
The consequence of no DD bit writeback is that the TX buffer descriptor cannot be released in the clean routine. The follow-up sent packets will exhaust all of the TX descriptors of the TX queue, and the the communition channel stalled completely.
The firmware behave is out of my scope, and I have no any more idears, could you please have a suggestion how to further debug for this issue?
I have tried to find any clue from document: "Intel® Ethernet Controller I210 Specification Update - Revision 3.0 332763-014".
Firstly, I focused on the errata item 31, the details as the following screenshoot. I doubtted that maybe the remote Linux server broadcasted certain IPv6 packets with malformed IPv6 extension header to cause I210 expected hehave. There suggested workaround in the document is to disable IPv6 _ExDis bit in the CFCTL register, but there is no this bit defined in I210 datasheet.
So could you please show me which states is correct ?
Thankd you in advance for your professional supports!
Regards,
Sam
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