From: "Russell King (Oracle)" <linux@armlinux.org.uk>
To: Vladimir Oltean <olteanv@gmail.com>
Cc: Jakub Kicinski <kuba@kernel.org>,
"David S. Miller" <davem@davemloft.net>,
netdev@vger.kernel.org, Florian Fainelli <f.fainelli@gmail.com>,
Andrew Lunn <andrew@lunn.ch>,
Vivien Didelot <vivien.didelot@gmail.com>,
Heiner Kallweit <hkallweit1@gmail.com>
Subject: Re: [RFC PATCH v2 linux-next 03/14] net: dsa: sja1105: the 0x1F0000 SGMII "base address" is actually MDIO_MMD_VEND2
Date: Wed, 26 May 2021 16:42:18 +0100 [thread overview]
Message-ID: <20210526154218.GI30436@shell.armlinux.org.uk> (raw)
In-Reply-To: <20210526153447.yjgbj5uhxxnvxvbs@skbuf>
On Wed, May 26, 2021 at 06:34:47PM +0300, Vladimir Oltean wrote:
> Hi Russell,
>
> On Wed, May 26, 2021 at 04:24:54PM +0100, Russell King (Oracle) wrote:
> > On Wed, May 26, 2021 at 04:55:24PM +0300, Vladimir Oltean wrote:
> > > - const struct sja1105_regs *regs = priv->info->regs;
> > > + u64 addr = (mmd << 16) | pcs_reg;
> >
> > What is the reason for using "u64" here. pcs_reg is 16-bits, and mmd is
> > five bits, which is well below 32 bits. So, why not u32?
>
> The "addr" variable holds a SPI address, and in the sja1105 driver, the
> SPI addresses are universally held in u64 variables, mainly because of
> the packing() API (Documentation/core-api/packing.rst).
As you are passing it into a function, the argument of which is a u64,
the compiler will promote the u32 to a u64 by itself. I guess it
doesn't actually matter, but the current code just looks really weird.
--
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
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next prev parent reply other threads:[~2021-05-26 15:42 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-26 13:55 [RFC PATCH v2 linux-next 00/14] Add NXP SJA1110 support to the sja1105 DSA driver Vladimir Oltean
2021-05-26 13:55 ` [RFC PATCH v2 linux-next 01/14] net: dsa: sja1105: be compatible with "ethernet-ports" OF node name Vladimir Oltean
2021-05-26 13:55 ` [RFC PATCH v2 linux-next 02/14] net: dsa: sja1105: allow SGMII PCS configuration to be per port Vladimir Oltean
2021-05-26 13:55 ` [RFC PATCH v2 linux-next 03/14] net: dsa: sja1105: the 0x1F0000 SGMII "base address" is actually MDIO_MMD_VEND2 Vladimir Oltean
2021-05-26 15:24 ` Russell King (Oracle)
2021-05-26 15:34 ` Vladimir Oltean
2021-05-26 15:42 ` Russell King (Oracle) [this message]
2021-05-26 13:55 ` [RFC PATCH v2 linux-next 04/14] net: dsa: sja1105: cache the phy-mode port property Vladimir Oltean
2021-05-26 13:55 ` [RFC PATCH v2 linux-next 05/14] net: dsa: sja1105: add a PHY interface type compatibility matrix Vladimir Oltean
2021-05-26 13:55 ` [RFC PATCH v2 linux-next 06/14] net: dsa: sja1105: add a translation table for port speeds Vladimir Oltean
2021-05-26 13:55 ` [RFC PATCH v2 linux-next 07/14] net: dsa: sja1105: always keep RGMII ports in the MAC role Vladimir Oltean
2021-05-26 13:55 ` [RFC PATCH v2 linux-next 08/14] net: dsa: sja1105: some table entries are always present when read dynamically Vladimir Oltean
2021-05-26 13:55 ` [RFC PATCH v2 linux-next 09/14] dt-bindings: net: dsa: sja1105: convert to YAML schema Vladimir Oltean
2021-05-26 13:55 ` [RFC PATCH v2 linux-next 10/14] dt-bindings: net: dsa: sja1105: add SJA1110 bindings Vladimir Oltean
2021-05-26 14:19 ` Rob Herring
2021-05-26 14:25 ` Vladimir Oltean
2021-05-26 13:55 ` [RFC PATCH v2 linux-next 11/14] net: dsa: sja1105: add support for the SJA1110 switch family Vladimir Oltean
2021-05-26 13:55 ` [RFC PATCH v2 linux-next 12/14] net: dsa: sja1105: register the MDIO buses for 100base-T1 and 100base-TX Vladimir Oltean
2021-05-26 13:55 ` [RFC PATCH v2 linux-next 13/14] net: dsa: sja1105: expose the SGMII PCS as an mdio_device Vladimir Oltean
2021-05-26 15:29 ` Russell King (Oracle)
2021-05-26 15:41 ` Vladimir Oltean
2021-05-26 15:46 ` Russell King (Oracle)
2021-05-26 21:26 ` Vladimir Oltean
2021-05-26 13:55 ` [RFC PATCH v2 linux-next 14/14] net: dsa: sja1105: add support for the SJA1110 SGMII/2500base-x PCS Vladimir Oltean
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