Messages in this thread | | | Date | Fri, 23 Apr 2021 03:53:08 +0300 | From | Vladimir Oltean <> | Subject | Re: [PATCH v2 net-next] net: pcs: Enable pre-emption packet for 10/100Mbps |
| |
On Fri, Apr 23, 2021 at 12:45:25AM +0000, Ismail, Mohammad Athari wrote: > Hi Vladimir, > > > -----Original Message----- > > From: Vladimir Oltean <olteanv@gmail.com> > > Sent: Friday, April 23, 2021 7:53 AM > > To: Ismail, Mohammad Athari <mohammad.athari.ismail@intel.com> > > Cc: Alexandre Torgue <alexandre.torgue@st.com>; Jose Abreu > > <joabreu@synopsys.com>; David S . Miller <davem@davemloft.net>; Jakub > > Kicinski <kuba@kernel.org>; Andrew Lunn <andrew@lunn.ch>; Heiner Kallweit > > <hkallweit1@gmail.com>; Russell King <linux@armlinux.org.uk>; Ong, Boon > > Leong <boon.leong.ong@intel.com>; Voon, Weifeng > > <weifeng.voon@intel.com>; Wong, Vee Khee <vee.khee.wong@intel.com>; > > netdev@vger.kernel.org; linux-kernel@vger.kernel.org > > Subject: Re: [PATCH v2 net-next] net: pcs: Enable pre-emption packet for > > 10/100Mbps > > > > Hi Mohammad, > > > > On Fri, Apr 23, 2021 at 07:06:45AM +0800, mohammad.athari.ismail@intel.com > > wrote: > > > From: Mohammad Athari Bin Ismail <mohammad.athari.ismail@intel.com> > > > > > > Set VR_MII_DIG_CTRL1 bit-6(PRE_EMP) to enable pre-emption packet for > > > 10/100Mbps by default. This setting doesn`t impact pre-emption > > > capability for other speeds. > > > > > > Signed-off-by: Mohammad Athari Bin Ismail > > > <mohammad.athari.ismail@intel.com> > > > --- > > > > What is a "pre-emption packet"? > > In IEEE 802.1 Qbu (Frame Preemption), pre-emption packet is used to > differentiate between MAC Frame packet, Express Packet, Non-fragmented > Normal Frame Packet, First Fragment of Preemptable Packet, > Intermediate Fragment of Preemptable Packet and Last Fragment of > Preemptable Packet.
Citation needed, which clause are you referring to?
> > This bit "VR_MII_DIG_CTRL1 bit-6(PRE_EMP)" defined in DesignWare Cores > Ethernet PCS Databook is to allow the IP to properly receive/transmit > pre-emption packets in SGMII 10M/100M Modes.
Shouldn't everything be handled at the MAC merge sublayer? What business does the PCS have in frame preemption?
Also, I know it's easy to forget, but Vinicius' patch series for supporting frame preemption via ethtool wasn't accepted yet. How are you testing this?
| |