Date: Thu, 21 Sep 2023 20:25:05 +0800
From: Choong Yong Liang <yong.liang.choong@...ux.intel.com>
To: Andrew Lunn <andrew@...n.ch>
Cc: Rajneesh Bhardwaj <irenic.rajneesh@...il.com>,
 David E Box <david.e.box@...ux.intel.com>,
 Hans de Goede <hdegoede@...hat.com>, Mark Gross <markgross@...nel.org>,
 Jose Abreu <Jose.Abreu@...opsys.com>, Heiner Kallweit
 <hkallweit1@...il.com>, Russell King <linux@...linux.org.uk>,
 "David S . Miller" <davem@...emloft.net>, Eric Dumazet
 <edumazet@...gle.com>, Jakub Kicinski <kuba@...nel.org>,
 Paolo Abeni <pabeni@...hat.com>, Marek Behún
 <kabel@...nel.org>, Jean Delvare <jdelvare@...e.com>,
 Guenter Roeck <linux@...ck-us.net>,
 Giuseppe Cavallaro <peppe.cavallaro@...com>,
 Alexandre Torgue <alexandre.torgue@...s.st.com>,
 Jose Abreu <joabreu@...opsys.com>,
 Maxime Coquelin <mcoquelin.stm32@...il.com>,
 Richard Cochran <richardcochran@...il.com>,
 Philipp Zabel <p.zabel@...gutronix.de>, Alexei Starovoitov <ast@...nel.org>,
 Daniel Borkmann <daniel@...earbox.net>,
 Jesper Dangaard Brouer <hawk@...nel.org>,
 John Fastabend <john.fastabend@...il.com>, Wong Vee Khee
 <veekhee@...le.com>, Jon Hunter <jonathanh@...dia.com>,
 Jesse Brandeburg <jesse.brandeburg@...el.com>,
 Revanth Kumar Uppala <ruppala@...dia.com>,
 Shenwei Wang <shenwei.wang@....com>,
 Andrey Konovalov <andrey.konovalov@...aro.org>,
 Jochen Henneberg <jh@...neberg-systemdesign.com>, netdev@...r.kernel.org,
 linux-kernel@...r.kernel.org, linux-stm32@...md-mailman.stormreply.com,
 linux-arm-kernel@...ts.infradead.org, platform-driver-x86@...r.kernel.org,
 linux-hwmon@...r.kernel.org, bpf@...r.kernel.org,
 Voon Wei Feng <weifeng.voon@...el.com>,
 Tan Tee Min <tee.min.tan@...ux.intel.com>,
 Michael Sit Wei Hong <michael.wei.hong.sit@...el.com>,
 Lai Peter Jun Ann <jun.ann.lai@...el.com>
Subject: Re: [PATCH net-next v2 0/5] TSN auto negotiation between 1G and 2.5G



On 4/8/2023 8:04 pm, Andrew Lunn wrote:
> On Fri, Aug 04, 2023 at 04:45:22PM +0800, Choong Yong Liang wrote:
>> Intel platforms’ integrated Gigabit Ethernet controllers support
>> 2.5Gbps mode statically using BIOS programming. In the current
>> implementation, the BIOS menu provides an option to select between
>> 10/100/1000Mbps and 2.5Gbps modes. Based on the selection, the BIOS
>> programs the Phase Lock Loop (PLL) registers. The BIOS also read the
>> TSN lane registers from Flexible I/O Adapter (FIA) block and provided
>> 10/100/1000Mbps/2.5Gbps information to the stmmac driver. But
>> auto-negotiation between 10/100/1000Mbps and 2.5Gbps is not allowed.
>> The new proposal is to support auto-negotiation between 10/100/1000Mbps
>> and 2.5Gbps . Auto-negotiation between 10, 100, 1000Mbps will use
>> in-band auto negotiation. Auto-negotiation between 10/100/1000Mbps and
>> 2.5Gbps will work as the following proposed flow, the stmmac driver reads
>> the PHY link status registers then identifies the negotiated speed.
>> Based on the speed stmmac driver will identify TSN lane registers from
>> FIA then send IPC command to the Power Management controller (PMC)
>> through PMC driver/API. PMC will act as a proxy to programs the
>> PLL registers.
> 
> Have you considered using out of band for all link modes? You might
> end up with a cleaner architecture, and not need any phylink/phylib
> hacks.
> 
> 	Andrew
Hi Andrew,

After conducting a comprehensive study, it seems that implementing 
out-of-band for all link modes might not be feasible. I may have missed 
some key aspects during my analysis.

Would you be open to sharing a high-level idea of how we could potentially 
make this feasible? Your insights would be greatly appreciated.

By the way, I've submitted a new design that not exposing phylink's AN mode 
into phylib. Please help review it to determine if it is acceptable.

Powered by blists - more mailing lists