RE: [v2, PATCH 3/4] net: stmmac: modify default value of tx-frames

[biao huang <biao.huang@mediatek.com>]

On Mon, 2019-06-03 at 11:40 +0000, Jose Abreu wrote:
> From: Biao Huang <biao.huang@mediatek.com>
> 
> > the default value of tx-frames is 25, it's too late when
> > passing tstamp to stack, then the ptp4l will fail:
> > 
> > ptp4l -i eth0 -f gPTP.cfg -m
> > ptp4l: selected /dev/ptp0 as PTP clock
> > ptp4l: port 1: INITIALIZING to LISTENING on INITIALIZE
> > ptp4l: port 0: INITIALIZING to LISTENING on INITIALIZE
> > ptp4l: port 1: link up
> > ptp4l: timed out while polling for tx timestamp
> > ptp4l: increasing tx_timestamp_timeout may correct this issue,
> >        but it is likely caused by a driver bug
> > ptp4l: port 1: send peer delay response failed
> > ptp4l: port 1: LISTENING to FAULTY on FAULT_DETECTED (FT_UNSPECIFIED)
> > 
> > ptp4l tests pass when changing the tx-frames from 25 to 1 with
> > ethtool -C option.
> > It should be fine to set tx-frames default value to 1, so ptp4l will pass
> > by default.
> 
> I'm not sure if this is the right approach ... What's the timeout value 
> you have for TX Timestamp ?
I use the default tx_timestamp_timeout value 1, which represents 1ms.
do you try ptp4l on your side?

performance test is done in https://lkml.org/lkml/2019/5/30/1617
and seems no performance degradation.

> 
> Thanks,
> Jose Miguel Abreu