Re: [PATCH CFT net-next 0/6] net: stmmac/xpcs: modernise PCS support

From: "Russell King (Oracle)" <linux@armlinux.org.uk>
To: Wong Vee Khee <vee.khee.wong@linux.intel.com>
Cc: Alexandre Torgue <alexandre.torgue@foss.st.com>,
	Giuseppe Cavallaro <peppe.cavallaro@st.com>,
	Jose Abreu <Jose.Abreu@synopsys.com>,
	Maxime Coquelin <mcoquelin.stm32@gmail.com>,
	Andrew Lunn <andrew@lunn.ch>,
	"David S. Miller" <davem@davemloft.net>,
	Heiner Kallweit <hkallweit1@gmail.com>,
	Jakub Kicinski <kuba@kernel.org>,
	Jose Abreu <joabreu@synopsys.com>,
	linux-arm-kernel@lists.infradead.org,
	linux-stm32@st-md-mailman.stormreply.com, netdev@vger.kernel.org
Subject: Re: [PATCH CFT net-next 0/6] net: stmmac/xpcs: modernise PCS support
Date: Fri, 7 Jan 2022 13:40:06 +0000	[thread overview]
Message-ID: <YdhCts9ZPMyzO8oX@shell.armlinux.org.uk> (raw)
In-Reply-To: <20211217055729.GA14835@linux.intel.com>

On Fri, Dec 17, 2021 at 01:57:29PM +0800, Wong Vee Khee wrote:
> On Thu, Dec 16, 2021 at 01:11:40PM +0000, Russell King (Oracle) wrote:
> > Hi,
> > 
> > This series updates xpcs and stmmac for the recent changes to phylink
> > to better support split PCS and to get rid of private MAC validation
> > functions.
> > 
> > This series is slightly more involved than other conversions as stmmac
> > has already had optional proper split PCS support.
> > 
> > The patches:
> > 
> > 1) Provide a function to query the xpcs for the interface modes that
> >    are supported.
> > 
> > 2) Populates the MAC capabilities and switches stmmac_validate() to use
> >    phylink_get_linkmodes(). We do not use phylink_generic_validate() yet
> >    as (a) we do not always have the supported interfaces populated, and
> >    (b) the existing code does not restrict based on interface. There
> >    should be no functional effect from this patch.
> > 
> > 3) Populates phylink's supported interfaces from the xpcs when the xpcs
> >    is configured by firmware and also the firmware configured interface
> >    mode. Note: this will restrict stmmac to only supporting these
> >    interfaces modes - stmmac maintainers need to verify that this
> >    behaviour is acceptable.
> > 
> > 4) stmmac_validate() tail-calls xpcs_validate(), but we don't need it to
> >    now that PCS have their own validation method. Convert stmmac and
> >    xpcs to use this method instead.
> > 
> > 5) xpcs sets the poll field of phylink_pcs to true, meaning xpcs
> >    requires its status to be polled. There is no need to also set the
> >    phylink_config.pcs_poll. Remove this.
> > 
> > 6) Switch to phylink_generic_validate(). This is probably the most
> >    contravertial change in this patch set as this will cause the MAC to
> >    restrict link modes based on the interface mode. From an inspection
> >    of the xpcs driver, this should be safe, as XPCS only further
> >    restricts the link modes to a subset of these (whether that is
> >    correct or not is not an issue I am addressing here.) For
> >    implementations that do not use xpcs, this is a more open question
> >    and needs feedback from stmmac maintainers.
> > 
> > Please review and test this series. Thanks!
> > 
> 
> Tested this patch series on my Intel Elkhart Lake setup with Marvell
> 88E1510 PHY. 
> 
> Everything works perfectly!

Can I take that as a tested-by please?

It would be good to get some feedback from other stmmac users, since I
believe stmmac is used in multiple different configurations.

Thanks!

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
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