On 22.03.2018 15:51, harinikatakamli...@gmail.com wrote:
> From: Harini Katakam <hari...@xilinx.com>
>
> Replace the while loop in MDIO read/write functions with a timeout.
> In addition, add a check for MDIO bus busy before initiating a new
> operation as well to make sure there is no ongoing MDIO operation.
>
> Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.da...@xilinx.com>
> Signed-off-by: Harini Katakam <hari...@xilinx.com>
> ---
> drivers/net/ethernet/cadence/macb_main.c | 54
> ++++++++++++++++++++++++++++++--
> 1 file changed, 52 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/ethernet/cadence/macb_main.c
> b/drivers/net/ethernet/cadence/macb_main.c
> index d09bd43..f4030c1 100644
> --- a/drivers/net/ethernet/cadence/macb_main.c
> +++ b/drivers/net/ethernet/cadence/macb_main.c
> @@ -321,6 +321,21 @@ static int macb_mdio_read(struct mii_bus *bus, int
> mii_id, int regnum)
> {
> struct macb *bp = bus->priv;
> int value;
> + ulong timeout;
> +
> + timeout = jiffies + msecs_to_jiffies(1000);
> + /* wait for end of transfer */
> + do {
> + if (MACB_BFEXT(IDLE, macb_readl(bp, NSR)))
> + break;
> +
> + cpu_relax();
> + } while (!time_after_eq(jiffies, timeout));
> +
> + if (time_after_eq(jiffies, timeout)) {
> + netdev_err(bp->dev, "wait for end of transfer timed out\n");
> + return -ETIMEDOUT;
> + }
Wouldn't be cleaner to keep it in this way:
while (!MACB_BFEXT(IDLE, macb_readl(bp, NSR))) {
if (time_after_eq(jiffies, timeout) {
netdev_err(bp->dev, "wait for end of transfer timed
out\n");
return -ETIMEDOUT;
}
cpu_relax();
}
>
> macb_writel(bp, MAN, (MACB_BF(SOF, MACB_MAN_SOF)
> | MACB_BF(RW, MACB_MAN_READ)
> @@ -328,9 +343,19 @@ static int macb_mdio_read(struct mii_bus *bus, int
> mii_id, int regnum)
> | MACB_BF(REGA, regnum)
> | MACB_BF(CODE, MACB_MAN_CODE)));
>
> + timeout = jiffies + msecs_to_jiffies(1000);
> /* wait for end of transfer */
> - while (!MACB_BFEXT(IDLE, macb_readl(bp, NSR)))
> + do {
> + if (MACB_BFEXT(IDLE, macb_readl(bp, NSR)))
> + break;
> +
> cpu_relax();
> + } while (!time_after_eq(jiffies, timeout));
> +
> + if (time_after_eq(jiffies, timeout)) {
> + netdev_err(bp->dev, "wait for end of transfer timed out\n");
> + return -ETIMEDOUT;
> + }
>
> value = MACB_BFEXT(DATA, macb_readl(bp, MAN));
>
> @@ -341,6 +366,21 @@ static int macb_mdio_write(struct mii_bus *bus, int
> mii_id, int regnum,
> u16 value)
> {
> struct macb *bp = bus->priv;
> + ulong timeout;
> +
> + timeout = jiffies + msecs_to_jiffies(1000);
> + /* wait for end of transfer */
> + do {
> + if (MACB_BFEXT(IDLE, macb_readl(bp, NSR)))
> + break;
> +
> + cpu_relax();
> + } while (!time_after_eq(jiffies, timeout));
> +
> + if (time_after_eq(jiffies, timeout)) {
> + netdev_err(bp->dev, "wait for end of transfer timed out\n");
> + return -ETIMEDOUT;
> + }
>
> macb_writel(bp, MAN, (MACB_BF(SOF, MACB_MAN_SOF)
> | MACB_BF(RW, MACB_MAN_WRITE)
> @@ -349,9 +389,19 @@ static int macb_mdio_write(struct mii_bus *bus, int
> mii_id, int regnum,
> | MACB_BF(CODE, MACB_MAN_CODE)
> | MACB_BF(DATA, value)));
>
> + timeout = jiffies + msecs_to_jiffies(1000);
> /* wait for end of transfer */
> - while (!MACB_BFEXT(IDLE, macb_readl(bp, NSR)))
> + do {
> + if (MACB_BFEXT(IDLE, macb_readl(bp, NSR)))
> + break;
> +
> cpu_relax();
> + } while (!time_after_eq(jiffies, timeout));
> +
> + if (time_after_eq(jiffies, timeout)) {
> + netdev_err(bp->dev, "wait for end of transfer timed out\n");
> + return -ETIMEDOUT;
> + }
>
> return 0;
> }
>
