linux-kernel - Re: [PATCH 07/17] net: stmmac: replace stmmac_mdio_busy_wait by readl_poll

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Date:   Tue, 31 Jan 2017 11:13:49 +0100
From:   Giuseppe CAVALLARO <peppe.cavallaro@...com>
To:     Corentin Labbe <clabbe.montjoie@...il.com>,
        <alexandre.torgue@...com>, <netdev@...r.kernel.org>
CC:     <davem@...emloft.net>, <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 07/17] net: stmmac: replace stmmac_mdio_busy_wait by
 readl_poll_timeout

On 1/31/2017 10:11 AM, Corentin Labbe wrote:
> The stmmac_mdio_busy_wait() function do the same job than
> readl_poll_timeout().
> So is is better to replace it.
>
> Signed-off-by: Corentin Labbe <clabbe.montjoie@...il.com>

I just wonder if you also tested it, this impacts all the platforms
where SMA block is used

if yes, pls consider my:

Acked-by: Giuseppe Cavallaro <peppe.cavallaro@...com>

> ---
>  drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c | 33 ++++++++---------------
>  1 file changed, 11 insertions(+), 22 deletions(-)
>
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
> index c24bef2..d9893cf 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
> @@ -21,6 +21,7 @@
>  *******************************************************************************/
>
>  #include <linux/io.h>
> +#include <linux/iopoll.h>
>  #include <linux/mii.h>
>  #include <linux/of.h>
>  #include <linux/of_gpio.h>
> @@ -38,22 +39,6 @@
>  #define MII_GMAC4_WRITE			(1 << MII_GMAC4_GOC_SHIFT)
>  #define MII_GMAC4_READ			(3 << MII_GMAC4_GOC_SHIFT)
>
> -static int stmmac_mdio_busy_wait(void __iomem *ioaddr, unsigned int mii_addr)
> -{
> -	unsigned long curr;
> -	unsigned long finish = jiffies + 3 * HZ;
> -
> -	do {
> -		curr = jiffies;
> -		if (readl(ioaddr + mii_addr) & MII_BUSY)
> -			cpu_relax();
> -		else
> -			return 0;
> -	} while (!time_after_eq(curr, finish));
> -
> -	return -EBUSY;
> -}
> -
>  /**
>   * stmmac_mdio_read
>   * @bus: points to the mii_bus structure
> @@ -70,7 +55,7 @@ static int stmmac_mdio_read(struct mii_bus *bus, int phyaddr, int phyreg)
>  	struct stmmac_priv *priv = netdev_priv(ndev);
>  	unsigned int mii_address = priv->hw->mii.addr;
>  	unsigned int mii_data = priv->hw->mii.data;
> -
> +	u32 v;
>  	int data;
>  	u32 value = MII_BUSY;
>
> @@ -82,12 +67,14 @@ static int stmmac_mdio_read(struct mii_bus *bus, int phyaddr, int phyreg)
>  	if (priv->plat->has_gmac4)
>  		value |= MII_GMAC4_READ;
>
> -	if (stmmac_mdio_busy_wait(priv->ioaddr, mii_address))
> +	if (readl_poll_timeout(priv->ioaddr + mii_address, v, !(v & MII_BUSY),
> +			       100, 10000))
>  		return -EBUSY;
>
>  	writel(value, priv->ioaddr + mii_address);
>
> -	if (stmmac_mdio_busy_wait(priv->ioaddr, mii_address))
> +	if (readl_poll_timeout(priv->ioaddr + mii_address, v, !(v & MII_BUSY),
> +			       100, 10000))
>  		return -EBUSY;
>
>  	/* Read the data from the MII data register */
> @@ -111,7 +98,7 @@ static int stmmac_mdio_write(struct mii_bus *bus, int phyaddr, int phyreg,
>  	struct stmmac_priv *priv = netdev_priv(ndev);
>  	unsigned int mii_address = priv->hw->mii.addr;
>  	unsigned int mii_data = priv->hw->mii.data;
> -
> +	u32 v;
>  	u32 value = MII_BUSY;
>
>  	value |= (phyaddr << priv->hw->mii.addr_shift)
> @@ -126,7 +113,8 @@ static int stmmac_mdio_write(struct mii_bus *bus, int phyaddr, int phyreg,
>  		value |= MII_WRITE;
>
>  	/* Wait until any existing MII operation is complete */
> -	if (stmmac_mdio_busy_wait(priv->ioaddr, mii_address))
> +	if (readl_poll_timeout(priv->ioaddr + mii_address, v, !(v & MII_BUSY),
> +			       100, 10000))
>  		return -EBUSY;
>
>  	/* Set the MII address register to write */
> @@ -134,7 +122,8 @@ static int stmmac_mdio_write(struct mii_bus *bus, int phyaddr, int phyreg,
>  	writel(value, priv->ioaddr + mii_address);
>
>  	/* Wait until any existing MII operation is complete */
> -	return stmmac_mdio_busy_wait(priv->ioaddr, mii_address);
> +	return readl_poll_timeout(priv->ioaddr + mii_address, v, !(v & MII_BUSY),
> +				  100, 10000);
>  }
>
>  /**
>