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Date: Sun, 14 Apr 2024 04:22:31 +0100
From: Daniel Golle <daniel@makrotopia.org>
To: arinc.unal@arinc9.com
Cc: DENG Qingfang <dqfext@gmail.com>, Sean Wang <sean.wang@mediatek.com>,
	Andrew Lunn <andrew@lunn.ch>,
	Florian Fainelli <f.fainelli@gmail.com>,
	Vladimir Oltean <olteanv@gmail.com>,
	"David S. Miller" <davem@davemloft.net>,
	Eric Dumazet <edumazet@google.com>,
	Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
	Matthias Brugger <matthias.bgg@gmail.com>,
	AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>,
	Bartel Eerdekens <bartel.eerdekens@constell8.be>,
	mithat.guner@xeront.com, erkin.bozoglu@xeront.com,
	netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	linux-mediatek@lists.infradead.org
Subject: Re: [PATCH net-next 2/2] net: dsa: mt7530: simplify core operations
Message-ID: <ZhtL9zAO83HJb_Jq@makrotopia.org>
References: <20240414-b4-for-netnext-mt7530-phy-addr-from-dt-and-simplify-core-ops-v1-0-b08936df2770@arinc9.com>
 <20240414-b4-for-netnext-mt7530-phy-addr-from-dt-and-simplify-core-ops-v1-2-b08936df2770@arinc9.com>
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In-Reply-To: <20240414-b4-for-netnext-mt7530-phy-addr-from-dt-and-simplify-core-ops-v1-2-b08936df2770@arinc9.com>

On Sun, Apr 14, 2024 at 01:08:20AM +0300, Arınç ÜNAL via B4 Relay wrote:
> From: Arınç ÜNAL <arinc.unal@arinc9.com>
> 
> The core_rmw() function calls core_read_mmd_indirect() to read the
> requested register, and then calls core_write_mmd_indirect() to write the
> requested value to the register. Because Clause 22 is used to access Clause
> 45 registers, some operations on core_write_mmd_indirect() are
> unnecessarily run. Get rid of core_read_mmd_indirect() and
> core_write_mmd_indirect(), and run only the necessary operations on
> core_write() and core_rmw().
> 
> Signed-off-by: Arınç ÜNAL <arinc.unal@arinc9.com>

Reviewed-by: Daniel Golle <daniel@makrotopia.org>
Tested-by: Daniel Golle <daniel@makrotopia.org>

> ---
>  drivers/net/dsa/mt7530.c | 108 +++++++++++++++++++----------------------------
>  1 file changed, 43 insertions(+), 65 deletions(-)
> 
> diff --git a/drivers/net/dsa/mt7530.c b/drivers/net/dsa/mt7530.c
> index fefa6dd151fa..2650eacf87a7 100644
> --- a/drivers/net/dsa/mt7530.c
> +++ b/drivers/net/dsa/mt7530.c
> @@ -74,116 +74,94 @@ static const struct mt7530_mib_desc mt7530_mib[] = {
>  	MIB_DESC(1, 0xb8, "RxArlDrop"),
>  };
>  
> -/* Since phy_device has not yet been created and
> - * phy_{read,write}_mmd_indirect is not available, we provide our own
> - * core_{read,write}_mmd_indirect with core_{clear,write,set} wrappers
> - * to complete this function.
> - */
> -static int
> -core_read_mmd_indirect(struct mt7530_priv *priv, int prtad, int devad)
> +static void
> +mt7530_mutex_lock(struct mt7530_priv *priv)
> +{
> +	if (priv->bus)
> +		mutex_lock_nested(&priv->bus->mdio_lock, MDIO_MUTEX_NESTED);
> +}
> +
> +static void
> +mt7530_mutex_unlock(struct mt7530_priv *priv)
> +{
> +	if (priv->bus)
> +		mutex_unlock(&priv->bus->mdio_lock);
> +}
> +
> +static void
> +core_write(struct mt7530_priv *priv, u32 reg, u32 val)
>  {
>  	struct mii_bus *bus = priv->bus;
> -	int value, ret;
> +	int ret;
> +
> +	mt7530_mutex_lock(priv);
>  
>  	/* Write the desired MMD Devad */
>  	ret = bus->write(bus, MT753X_CTRL_PHY_ADDR(priv->phy_addr),
> -			 MII_MMD_CTRL, devad);
> +			 MII_MMD_CTRL, MDIO_MMD_VEND2);
>  	if (ret < 0)
>  		goto err;
>  
>  	/* Write the desired MMD register address */
>  	ret = bus->write(bus, MT753X_CTRL_PHY_ADDR(priv->phy_addr),
> -			 MII_MMD_DATA, prtad);
> +			 MII_MMD_DATA, reg);
>  	if (ret < 0)
>  		goto err;
>  
>  	/* Select the Function : DATA with no post increment */
>  	ret = bus->write(bus, MT753X_CTRL_PHY_ADDR(priv->phy_addr),
> -			 MII_MMD_CTRL, devad | MII_MMD_CTRL_NOINCR);
> +			 MII_MMD_CTRL, MDIO_MMD_VEND2 | MII_MMD_CTRL_NOINCR);
>  	if (ret < 0)
>  		goto err;
>  
> -	/* Read the content of the MMD's selected register */
> -	value = bus->read(bus, MT753X_CTRL_PHY_ADDR(priv->phy_addr),
> -			  MII_MMD_DATA);
> -
> -	return value;
> +	/* Write the data into MMD's selected register */
> +	ret = bus->write(bus, MT753X_CTRL_PHY_ADDR(priv->phy_addr),
> +			 MII_MMD_DATA, val);
>  err:
> -	dev_err(&bus->dev,  "failed to read mmd register\n");
> +	if (ret < 0)
> +		dev_err(&bus->dev, "failed to write mmd register\n");
>  
> -	return ret;
> +	mt7530_mutex_unlock(priv);
>  }
>  
> -static int
> -core_write_mmd_indirect(struct mt7530_priv *priv, int prtad,
> -			int devad, u32 data)
> +static void
> +core_rmw(struct mt7530_priv *priv, u32 reg, u32 mask, u32 set)
>  {
>  	struct mii_bus *bus = priv->bus;
> +	u32 val;
>  	int ret;
>  
> +	mt7530_mutex_lock(priv);
> +
>  	/* Write the desired MMD Devad */
>  	ret = bus->write(bus, MT753X_CTRL_PHY_ADDR(priv->phy_addr),
> -			 MII_MMD_CTRL, devad);
> +			 MII_MMD_CTRL, MDIO_MMD_VEND2);
>  	if (ret < 0)
>  		goto err;
>  
>  	/* Write the desired MMD register address */
>  	ret = bus->write(bus, MT753X_CTRL_PHY_ADDR(priv->phy_addr),
> -			 MII_MMD_DATA, prtad);
> +			 MII_MMD_DATA, reg);
>  	if (ret < 0)
>  		goto err;
>  
>  	/* Select the Function : DATA with no post increment */
>  	ret = bus->write(bus, MT753X_CTRL_PHY_ADDR(priv->phy_addr),
> -			 MII_MMD_CTRL, devad | MII_MMD_CTRL_NOINCR);
> +			 MII_MMD_CTRL, MDIO_MMD_VEND2 | MII_MMD_CTRL_NOINCR);
>  	if (ret < 0)
>  		goto err;
>  
> +	/* Read the content of the MMD's selected register */
> +	val = bus->read(bus, MT753X_CTRL_PHY_ADDR(priv->phy_addr),
> +			MII_MMD_DATA);
> +	val &= ~mask;
> +	val |= set;
>  	/* Write the data into MMD's selected register */
>  	ret = bus->write(bus, MT753X_CTRL_PHY_ADDR(priv->phy_addr),
> -			 MII_MMD_DATA, data);
> +			 MII_MMD_DATA, val);
>  err:
>  	if (ret < 0)
> -		dev_err(&bus->dev,
> -			"failed to write mmd register\n");
> -	return ret;
> -}
> -
> -static void
> -mt7530_mutex_lock(struct mt7530_priv *priv)
> -{
> -	if (priv->bus)
> -		mutex_lock_nested(&priv->bus->mdio_lock, MDIO_MUTEX_NESTED);
> -}
> -
> -static void
> -mt7530_mutex_unlock(struct mt7530_priv *priv)
> -{
> -	if (priv->bus)
> -		mutex_unlock(&priv->bus->mdio_lock);
> -}
> -
> -static void
> -core_write(struct mt7530_priv *priv, u32 reg, u32 val)
> -{
> -	mt7530_mutex_lock(priv);
> -
> -	core_write_mmd_indirect(priv, reg, MDIO_MMD_VEND2, val);
> -
> -	mt7530_mutex_unlock(priv);
> -}
> -
> -static void
> -core_rmw(struct mt7530_priv *priv, u32 reg, u32 mask, u32 set)
> -{
> -	u32 val;
> -
> -	mt7530_mutex_lock(priv);
> -
> -	val = core_read_mmd_indirect(priv, reg, MDIO_MMD_VEND2);
> -	val &= ~mask;
> -	val |= set;
> -	core_write_mmd_indirect(priv, reg, MDIO_MMD_VEND2, val);
> +		dev_err(&bus->dev, "failed to write mmd register\n");
>  
>  	mt7530_mutex_unlock(priv);
>  }
> 
> -- 
> 2.40.1
> 
>