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Improve busy-wait loop during switch phy access in e6000sw

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Hitherto implementation of PHY polling resulted in a risk of an
endless loop and very high occupation of the SMI bus. Improve the
operation by limiting the polling tries and adding sleepable
pause.

Submitted by: Marcin Wojtas <mw@semihalf.com>
Obtained from: Semihalf
Sponsored by: Stormshield
Reviewed by: loos
Differential revision: https://reviews.freebsd.org/D10713
This commit is contained in:
wma 2017-05-19 08:16:47 +00:00
parent 9534fa80c9
commit b854df5591
1 changed files with 39 additions and 8 deletions
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47
sys/dev/etherswitch/e6000sw/e6000sw.c
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@ -431,13 +431,21 @@ out_fail:
return (err);
}
static __inline void
static __inline int
e6000sw_poll_done(e6000sw_softc_t *sc)
{
int i;
while (e6000sw_readreg(sc, REG_GLOBAL2, PHY_CMD) &
(1 << PHY_CMD_SMI_BUSY))
continue;
for (i = 0; i < 16; i++) {
if (!(e6000sw_readreg(sc, REG_GLOBAL2, PHY_CMD) &
(1 << PHY_CMD_SMI_BUSY)))
return (0);
pause("e6000sw PHY poll", hz/1000);
}
return (ETIMEDOUT);
}
/*
@ -449,6 +457,7 @@ e6000sw_readphy(device_t dev, int phy, int reg)
{
e6000sw_softc_t *sc;
uint32_t val;
int err;
sc = device_get_softc(dev);
val = 0;
@ -460,14 +469,25 @@ e6000sw_readphy(device_t dev, int phy, int reg)
E6000SW_LOCK_ASSERT(sc, SA_XLOCKED);
e6000sw_poll_done(sc);
err = e6000sw_poll_done(sc);
if (err != 0) {
device_printf(dev, "Timeout while waiting for switch\n");
return (err);
}
val |= 1 << PHY_CMD_SMI_BUSY;
val |= PHY_CMD_MODE_MDIO << PHY_CMD_MODE;
val |= PHY_CMD_OPCODE_READ << PHY_CMD_OPCODE;
val |= (reg << PHY_CMD_REG_ADDR) & PHY_CMD_REG_ADDR_MASK;
val |= (phy << PHY_CMD_DEV_ADDR) & PHY_CMD_DEV_ADDR_MASK;
e6000sw_writereg(sc, REG_GLOBAL2, SMI_PHY_CMD_REG, val);
e6000sw_poll_done(sc);
err = e6000sw_poll_done(sc);
if (err != 0) {
device_printf(dev, "Timeout while waiting for switch\n");
return (err);
}
val = e6000sw_readreg(sc, REG_GLOBAL2, SMI_PHY_DATA_REG)
& PHY_DATA_MASK;
@ -479,6 +499,7 @@ e6000sw_writephy(device_t dev, int phy, int reg, int data)
{
e6000sw_softc_t *sc;
uint32_t val;
int err;
sc = device_get_softc(dev);
val = 0;
@ -490,7 +511,12 @@ e6000sw_writephy(device_t dev, int phy, int reg, int data)
E6000SW_LOCK_ASSERT(sc, SA_XLOCKED);
e6000sw_poll_done(sc);
err = e6000sw_poll_done(sc);
if (err != 0) {
device_printf(dev, "Timeout while waiting for switch\n");
return (err);
}
val |= PHY_CMD_MODE_MDIO << PHY_CMD_MODE;
val |= 1 << PHY_CMD_SMI_BUSY;
val |= PHY_CMD_OPCODE_WRITE << PHY_CMD_OPCODE;
@ -499,7 +525,12 @@ e6000sw_writephy(device_t dev, int phy, int reg, int data)
e6000sw_writereg(sc, REG_GLOBAL2, SMI_PHY_DATA_REG,
data & PHY_DATA_MASK);
e6000sw_writereg(sc, REG_GLOBAL2, SMI_PHY_CMD_REG, val);
e6000sw_poll_done(sc);
err = e6000sw_poll_done(sc);
if (err != 0) {
device_printf(dev, "Timeout while waiting for switch\n");
return (err);
}
return (0);
}