[dpdk-dev] [PATCH v2] ether: use a default for max Rx frame size in configure()

[Bruce Richardson]

On Mon, Mar 27, 2017 at 10:38:13AM +0200, Andriy Berestovskyy wrote:
> Hey Qiming,
> 
> On 27.03.2017 08:15, Yang, Qiming wrote:
> > I don't think this is a bug. Return errors when configure an invalid max_rx_pkt_len is suitable for this generic API.
> 
> It is not a bug, it is an inconsistency. At the moment we can set
> max_rx_pkt_len for normal frames and if it is out of range a default value
> will be used instead.
> 
> IMO we should expect the same behavior from the same function for the jumbo
> frames.
> 
> So at the moment we have:
> jumbo == 0, max_rx_pkt_len == 0, result: max_rx_pkt_len = ETHER_MAX_LEN
> jumbo == 0, max_rx_pkt_len == 1200, result: max_rx_pkt_len = 1200

Is this really the case right now. My understanding was that when jumbo
== 0 max_rx_pkt_len is ignored. At least on Intel NICS, I believe the
max_rx_pkt_len is always 1518 unless jumbo frame support is explicitly
enabled. [Perhaps the driver maintainers can confirm this for me.]

Regards,
/Bruce