gianfar.c: Unwanted VLAN tagging on TX frames
to-fleischer at t-online.de
Wed Aug 26 03:08:55 EST 2009
On Tuesday 25 August 2009 at 01:32:18, Andy Fleming wrote:
> Hmmm....how have you tested this? This looks like it has a bad race
> condition. The TCTRL register applies to all packets, which means if you
> send a packet with VLAN tags, followed by one without, or visa versa,
> there's a reasonable chance that the second packet's VLAN tags (or lack
> thereof) will take precedence.
> Without speaking for the company, I suspect that this is just how the eTSEC
> works with VLAN -- all, or nothing.
I have tested it by sending a single ping to a station within the VLAN
followed by a ping to a station thats not in a VLAN.
OK, thats not really a significant test, because I did not send a VLAN tagged
frame immediately followed by one without a tag.
You are right, this code can enable/disable VLAN tagging before the previous
packet is processed.
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