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 11:39:01 +0100
From:   Corentin Labbe <clabbe.montjoie@...il.com>
To:     Giuseppe CAVALLARO <peppe.cavallaro@...com>
Cc:     alexandre.torgue@...com, netdev@...r.kernel.org,
        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 Tue, Jan 31, 2017 at 11:13:49AM +0100, Giuseppe CAVALLARO wrote:
> 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

I have tested all patch in this series on my cubieboard2 (dwmac-sunxi) and my opipc/pine64/bpim2+ (dwmac-sun8i)
(Yes I could have said that in cover letter).
So this code was tested on two different stmmac glue driver.

> 
> 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);
> >  }
> >
> >  /**
> >
>