Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Date:   Tue, 17 Aug 2021 15:32:26 +0100
From:   "Russell King (Oracle)" <linux@armlinux.org.uk>
To:     Jie Luo <luoj@codeaurora.org>
Cc:     Andrew Lunn <andrew@lunn.ch>, hkallweit1@gmail.com,
        davem@davemloft.net, kuba@kernel.org, linux-kernel@vger.kernel.org,
        netdev@vger.kernel.org, sricharan@codeaurora.org
Subject: Re: [PATCH] net: phy: add qca8081 ethernet phy driver
Message-ID: <20210817143226.GL22278@shell.armlinux.org.uk>
References: <20210816113440.22290-1-luoj@codeaurora.org>
 <YRpuhIcwN2IsaHzy@lunn.ch>
 <6856a839-0fa0-1240-47cd-ae8536294bcd@codeaurora.org>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
Content-Transfer-Encoding: 8bit
In-Reply-To: <6856a839-0fa0-1240-47cd-ae8536294bcd@codeaurora.org>
User-Agent: Mutt/1.10.1 (2018-07-13)
Sender: Russell King (Oracle) <linux@armlinux.org.uk>
Precedence: bulk

On Tue, Aug 17, 2021 at 09:10:44PM +0800, Jie Luo wrote:
> 
> On 8/16/2021 9:56 PM, Andrew Lunn wrote:
> > On Mon, Aug 16, 2021 at 07:34:40PM +0800, Luo Jie wrote:
> > > qca8081 is industry’s lowest cost and power 1-port 2.5G/1G Ethernet PHY
> > > chip, which implements SGMII/SGMII+ for interface to SoC.
> > Hi Luo
> > 
> > No Marketing claims in the commit message please. Even if it is
> > correct now, it will soon be wrong with newer generations of
> > devices.
> > 
> > And what is SGMII+? Please reference a document. Is it actually
> > 2500BaseX?
> 
> Hi Andrew,
> 
> thanks for the comments, will remove the claims in the next patch.
> 
> SGMII+ is for 2500BaseX, which is same as SGMII, but the clock frequency of
> SGMII+ is 2.5 times SGMII.

Bah. Sounds like more industry wide misunderstanding of what SGMII
vs 1000Base-X is to me... or just plain abuse of the term "SGMII"!

I think you'll find that "SGMII+" is nothing but a term Qualcomm use
to refer to 2500BASE-X without the 16-bit in-band control word to
the host.

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!