RE: [PATCH net-next 0/3] net: stmmac: Convert to phylink

From: Jose Abreu <Jose.Abreu@synopsys.com>
To: "Ondřej Jirman" <megi@xff.cz>, "Jose Abreu" <Jose.Abreu@synopsys.com>
Cc: Andrew Lunn <andrew@lunn.ch>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
	Joao Pinto <Joao.Pinto@synopsys.com>,
	"David S . Miller" <davem@davemloft.net>,
	Giuseppe Cavallaro <peppe.cavallaro@st.com>,
	Alexandre Torgue <alexandre.torgue@st.com>,
	Russell King <linux@armlinux.org.uk>,
	Florian Fainelli <f.fainelli@gmail.com>,
	"Heiner Kallweit" <hkallweit1@gmail.com>
Subject: RE: [PATCH net-next 0/3] net: stmmac: Convert to phylink
Date: Tue, 23 Jul 2019 09:36:42 +0000	[thread overview]
Message-ID: <BYAPR12MB32694541534ED0ABA3C55BE6D3C70@BYAPR12MB3269.namprd12.prod.outlook.com> (raw)
In-Reply-To: <20190722143955.uwzvcmhc4bdr2zr5@core.my.home>

From: Ondřej Jirman <megi@xff.cz>
Date: Jul/22/2019, 15:39:55 (UTC+00:00)

> On Mon, Jul 22, 2019 at 02:26:45PM +0000, Jose Abreu wrote:
> > From: Andrew Lunn <andrew@lunn.ch>
> > Date: Jul/22/2019, 15:19:43 (UTC+00:00)
> > 
> > > On Mon, Jul 22, 2019 at 01:58:20PM +0000, Jose Abreu wrote:
> > > > From: Andrew Lunn <andrew@lunn.ch>
> > > > Date: Jul/22/2019, 14:40:23 (UTC+00:00)
> > > > 
> > > > > Does this mean that all stmmac variants support 1G? There are none
> > > > > which just support Fast Ethernet?
> > > > 
> > > > This glue logic drivers sometimes reflect a custom IP that's Synopsys 
> > > > based but modified by customer, so I can't know before-hand what's the 
> > > > supported max speed. There are some old versions that don't support 1G 
> > > > but I expect that PHY driver limits this ...
> > > 
> > > If a Fast PHY is used, then yes, it would be limited. But sometimes a
> > > 1G PHY is used because they are cheaper than a Fast PHY.
> > >  
> > > > > I'm also not sure the change fits the problem. Why did it not
> > > > > negotiate 100FULL rather than 10Half? You are only moving the 1G
> > > > > speeds around, so 100 speeds should of been advertised and selected.
> > > > 
> > > > Hmm, now that I'm looking at it closer I agree with you. Maybe link 
> > > > partner or PHY doesn't support 100M ?
> > > 
> > > In the working case, ethtool shows the link partner supports 10, 100,
> > > and 1G. So something odd is going on here.
> > > 
> > > You fix does seems reasonable, and it has been reported to fix the
> > > issue, but it would be good to understand what is going on here.
> > 
> > Agreed!
> > 
> > Ondrej, can you please share dmesg log and ethtool output with the fixed 
> > patch ?
> 
> See the attachment, or this link:

So, I've removed all 1G link modes from stmmac and run it on an ARM 
based board. My link status resolves to 100M/Full using Generic PHY so 
maybe something is wrong with the PHY driver that Ondrej is using 
("RTL8211E Gigabit Ethernet") ?

---
Thanks,
Jose Miguel Abreu