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Date:   Fri, 23 Apr 2021 03:57:32 +0200
From:   Ansuel Smith <ansuelsmth@gmail.com>
To:     Florian Fainelli <f.fainelli@gmail.com>
Cc:     Andrew Lunn <andrew@lunn.ch>,
        Vivien Didelot <vivien.didelot@gmail.com>,
        Vladimir Oltean <olteanv@gmail.com>,
        "David S. Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        Heiner Kallweit <hkallweit1@gmail.com>,
        Russell King <linux@armlinux.org.uk>, netdev@vger.kernel.org,
        devicetree@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 02/14] drivers: net: dsa: qca8k: tweak internal delay to
 oem spec
Message-ID: <YIIpjBH8hZH/MaS7@Ansuel-xps.localdomain>
References: <20210423014741.11858-1-ansuelsmth@gmail.com>
 <20210423014741.11858-3-ansuelsmth@gmail.com>
 <fdddeb1a-33c7-3087-86a1-f3b735a90eb1@gmail.com>
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On Thu, Apr 22, 2021 at 06:53:45PM -0700, Florian Fainelli wrote:
> 
> 
> On 4/22/2021 6:47 PM, Ansuel Smith wrote:
> > The original code had the internal dalay set to 1 for tx and 2 for rx.
> > Apply the oem internal dalay to fix some switch communication error.
> > 
> > Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
> > ---
> >  drivers/net/dsa/qca8k.c | 6 ++++--
> >  drivers/net/dsa/qca8k.h | 9 ++++-----
> >  2 files changed, 8 insertions(+), 7 deletions(-)
> > 
> > diff --git a/drivers/net/dsa/qca8k.c b/drivers/net/dsa/qca8k.c
> > index a6d35b825c0e..b8bfc7acf6f4 100644
> > --- a/drivers/net/dsa/qca8k.c
> > +++ b/drivers/net/dsa/qca8k.c
> > @@ -849,8 +849,10 @@ qca8k_phylink_mac_config(struct dsa_switch *ds, int port, unsigned int mode,
> >  		 */
> >  		qca8k_write(priv, reg,
> >  			    QCA8K_PORT_PAD_RGMII_EN |
> > -			    QCA8K_PORT_PAD_RGMII_TX_DELAY(QCA8K_MAX_DELAY) |
> > -			    QCA8K_PORT_PAD_RGMII_RX_DELAY(QCA8K_MAX_DELAY));
> > +			    QCA8K_PORT_PAD_RGMII_TX_DELAY(1) |
> > +			    QCA8K_PORT_PAD_RGMII_RX_DELAY(2) |
> > +			    QCA8K_PORT_PAD_RGMII_TX_DELAY_EN |
> > +			    QCA8K_PORT_PAD_RGMII_RX_DELAY_EN);
> 
> There are standard properties in order to configure a specific RX and TX
> delay:
> 
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/devicetree/bindings/net/ethernet-controller.yaml#n125
> 
> can you use that mechanism and parse that property, or if nothing else,
> allow an user to override delays via device tree using these standard
> properties?

Since this is mac config, what would be the best way to parse these
data? Parse them in the qca8k_setup and put them in the
qca8k_priv?

> -- 
> Florian