From 59399c59262bbb8ae60a37935c3a512d2e79cca3 Mon Sep 17 00:00:00 2001 From: Timur Tabi Date: Mon, 9 Jul 2012 16:57:36 -0500 Subject: [PATCH] net/fsl_pq_mdio: use spin_event_timeout() to poll the indicator register Macro spin_event_timeout() was designed for simple polling of hardware registers with a timeout, so use it when we poll the MIIMIND register. This allows us to return an error code instead of polling indefinitely. Note that PHY_INIT_TIMEOUT is a count of loop iterations, so we can't use it for spin_event_timeout(), which asks for microseconds. Signed-off-by: Timur Tabi Signed-off-by: David S. Miller --- drivers/net/ethernet/freescale/fsl_pq_mdio.c | 29 +++++++++++++------- 1 file changed, 19 insertions(+), 10 deletions(-) diff --git a/drivers/net/ethernet/freescale/fsl_pq_mdio.c b/drivers/net/ethernet/freescale/fsl_pq_mdio.c index f7f0bf5d037b..9527b28d70d1 100644 --- a/drivers/net/ethernet/freescale/fsl_pq_mdio.c +++ b/drivers/net/ethernet/freescale/fsl_pq_mdio.c @@ -47,6 +47,9 @@ #include "gianfar.h" #include "fsl_pq_mdio.h" +/* Number of microseconds to wait for an MII register to respond */ +#define MII_TIMEOUT 1000 + struct fsl_pq_mdio_priv { void __iomem *map; struct fsl_pq_mdio __iomem *regs; @@ -64,6 +67,8 @@ struct fsl_pq_mdio_priv { int fsl_pq_local_mdio_write(struct fsl_pq_mdio __iomem *regs, int mii_id, int regnum, u16 value) { + u32 status; + /* Set the PHY address and the register address we want to write */ out_be32(®s->miimadd, (mii_id << 8) | regnum); @@ -71,10 +76,10 @@ int fsl_pq_local_mdio_write(struct fsl_pq_mdio __iomem *regs, int mii_id, out_be32(®s->miimcon, value); /* Wait for the transaction to finish */ - while (in_be32(®s->miimind) & MIIMIND_BUSY) - cpu_relax(); + status = spin_event_timeout(!(in_be32(®s->miimind) & MIIMIND_BUSY), + MII_TIMEOUT, 0); - return 0; + return status ? 0 : -ETIMEDOUT; } /* @@ -91,6 +96,7 @@ int fsl_pq_local_mdio_read(struct fsl_pq_mdio __iomem *regs, int mii_id, int regnum) { u16 value; + u32 status; /* Set the PHY address and the register address we want to read */ out_be32(®s->miimadd, (mii_id << 8) | regnum); @@ -99,9 +105,12 @@ int fsl_pq_local_mdio_read(struct fsl_pq_mdio __iomem *regs, out_be32(®s->miimcom, 0); out_be32(®s->miimcom, MII_READ_COMMAND); - /* Wait for the transaction to finish */ - while (in_be32(®s->miimind) & (MIIMIND_NOTVALID | MIIMIND_BUSY)) - cpu_relax(); + /* Wait for the transaction to finish, normally less than 100us */ + status = spin_event_timeout(!(in_be32(®s->miimind) & + (MIIMIND_NOTVALID | MIIMIND_BUSY)), + MII_TIMEOUT, 0); + if (!status) + return -ETIMEDOUT; /* Grab the value of the register from miimstat */ value = in_be32(®s->miimstat); @@ -144,7 +153,7 @@ int fsl_pq_mdio_read(struct mii_bus *bus, int mii_id, int regnum) static int fsl_pq_mdio_reset(struct mii_bus *bus) { struct fsl_pq_mdio __iomem *regs = fsl_pq_mdio_get_regs(bus); - int timeout = PHY_INIT_TIMEOUT; + u32 status; mutex_lock(&bus->mdio_lock); @@ -155,12 +164,12 @@ static int fsl_pq_mdio_reset(struct mii_bus *bus) out_be32(®s->miimcfg, MIIMCFG_INIT_VALUE); /* Wait until the bus is free */ - while ((in_be32(®s->miimind) & MIIMIND_BUSY) && timeout--) - cpu_relax(); + status = spin_event_timeout(!(in_be32(®s->miimind) & MIIMIND_BUSY), + MII_TIMEOUT, 0); mutex_unlock(&bus->mdio_lock); - if (timeout < 0) { + if (!status) { printk(KERN_ERR "%s: The MII Bus is stuck!\n", bus->name); return -EBUSY; -- 2.20.1