Subject: Re: [PATCH net-next v3 08/14] net: ethernet: oa_tc6: Remove FCS size in RX frame

From: Qingfang Deng <[email-masked]>
Date: Tue, 2 Jun 2026 11:01:06 +0800

On Tue, 2 Jun 2026 at 02:40:13, Selvamani Rajagopal wrote:
> But strangely ptp4l utility failed with invalid data size. Once we removed FCS, it worked fine.

This is because ptp4l misinterprets the FCS as a TLV. There are already
several discussions and patches about this issue, however the maintainer
insists that the ethernet driver needs to be fixed instead:

https://sourceforge.net/p/linuxptp/mailman/message/37858618/
https://sourceforge.net/p/linuxptp/mailman/linuxptp-devel/thread/20190205170652.476c9676%40redhat.com/#msg36579297
https://sourceforge.net/p/linuxptp/mailman/linuxptp-devel/thread/CA%2BDf%2BjcRN98GpUi%3DF_4Ls7miEPbUZYb8O-gpSw0TQoqczVqMfw%40mail.gmail.com/#msg37858491
https://sourceforge.net/p/linuxptp/mailman/linuxptp-devel/thread/8ed1dc74-bf4c-2f13-4ed0-a70d0c4512f6%40cisco.com/#msg37137818

Regards,
Qingfang