diff options
| author | Bryan Wu <bryan.wu@canonical.com> | 2010-04-22 14:12:02 +0800 |
|---|---|---|
| committer | Rob Herring <r.herring@freescale.com> | 2010-05-05 17:41:32 -0500 |
| commit | 16722dcd109ce9a2aed9e9a6e49e196bf6ac924a (patch) | |
| tree | 7a26fb192a673b93566f7cd7a87ff108c9289c5d /drivers | |
| parent | 8e716e445a4411cca7274a12320d5e74df13f47b (diff) | |
UBUNTU: SAUCE: (upstream) netdev/fec: fix performance impact from mdio poll operation
BugLink: http://bugs.launchpad.net/bugs/546649
BugLink: http://bugs.launchpad.net/bugs/457878
After introducing phylib supporting, users experienced performace drop. That is
because of the mdio polling operation of phylib. Use msleep to replace the busy
waiting cpu_relax() and remove the warning message.
Signed-off-by: Bryan Wu <bryan.wu@canonical.com>
Acked-by: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Andy Whitcroft <apw@canonical.com>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/net/fec.c | 45 |
1 files changed, 21 insertions, 24 deletions
diff --git a/drivers/net/fec.c b/drivers/net/fec.c index 29adc810fce8..f75bdd479710 100644 --- a/drivers/net/fec.c +++ b/drivers/net/fec.c @@ -225,7 +225,7 @@ static void fec_stop(struct net_device *dev); #define FEC_MMFR_TA (2 << 16) #define FEC_MMFR_DATA(v) (v & 0xffff) -#define FEC_MII_TIMEOUT 10000 +#define FEC_MII_TIMEOUT 10 /* Transmitter timeout */ #define TX_TIMEOUT (2 * HZ) @@ -651,12 +651,28 @@ spin_unlock: /* * NOTE: a MII transaction is during around 25 us, so polling it... */ +static int fec_enet_mdio_poll(struct fec_enet_private *fep) + { + int timeout = FEC_MII_TIMEOUT; + + fep->mii_timeout = 0; + + /* wait for end of transfer */ + while (!(readl(fep->hwp + FEC_IEVENT) & FEC_ENET_MII)) { + msleep(1); + if (timeout-- < 0) { + fep->mii_timeout = 1; + break; + } + } + + return 0; +} + static int fec_enet_mdio_read(struct mii_bus *bus, int mii_id, int regnum) { struct fec_enet_private *fep = bus->priv; - int timeout = FEC_MII_TIMEOUT; - fep->mii_timeout = 0; /* clear MII end of transfer bit*/ writel(FEC_ENET_MII, fep->hwp + FEC_IEVENT); @@ -666,15 +682,7 @@ static int fec_enet_mdio_read(struct mii_bus *bus, int mii_id, int regnum) FEC_MMFR_PA(mii_id) | FEC_MMFR_RA(regnum) | FEC_MMFR_TA, fep->hwp + FEC_MII_DATA); - /* wait for end of transfer */ - while (!(readl(fep->hwp + FEC_IEVENT) & FEC_ENET_MII)) { - cpu_relax(); - if (timeout-- < 0) { - fep->mii_timeout = 1; - printk(KERN_ERR "FEC: MDIO read timeout\n"); - return -ETIMEDOUT; - } - } + fec_enet_mdio_poll(fep); /* return value */ return FEC_MMFR_DATA(readl(fep->hwp + FEC_MII_DATA)); @@ -684,9 +692,6 @@ static int fec_enet_mdio_write(struct mii_bus *bus, int mii_id, int regnum, u16 value) { struct fec_enet_private *fep = bus->priv; - int timeout = FEC_MII_TIMEOUT; - - fep->mii_timeout = 0; /* clear MII end of transfer bit*/ writel(FEC_ENET_MII, fep->hwp + FEC_IEVENT); @@ -697,15 +702,7 @@ static int fec_enet_mdio_write(struct mii_bus *bus, int mii_id, int regnum, FEC_MMFR_TA | FEC_MMFR_DATA(value), fep->hwp + FEC_MII_DATA); - /* wait for end of transfer */ - while (!(readl(fep->hwp + FEC_IEVENT) & FEC_ENET_MII)) { - cpu_relax(); - if (timeout-- < 0) { - fep->mii_timeout = 1; - printk(KERN_ERR "FEC: MDIO write timeout\n"); - return -ETIMEDOUT; - } - } + fec_enet_mdio_poll(fep); return 0; } |