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generic: drop support for get_port_stats() on ar8xxx

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The implementation is not efficient on ar8xxx switches. It triggers high
CPU load and degrades device performance.

The high CPU load has been traced down to the ar8xxx_reg_wait() call in
ar8xxx_mib_op(), which has to usleep_range() till the MIB busy flag set
by the request to update the MIB counter is cleared.

This commit removes the get_port_stats() code introduced in 4d8a66d and
leaves a note for future hacker's beware.

Fixes: FS#1004

Signed-off-by: Thibaut VARENE <hacks@slashdirt.org>
This commit is contained in:
Thibaut VARENE 2017-09-12 23:22:37 +02:00 committed by Mathias Kresin
parent fd84ecda7d
commit eff3549c58
3 changed files with 18 additions and 59 deletions
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65
target/linux/generic/files/drivers/net/phy/ar8216.c
View file

@ -49,12 +49,6 @@ extern const struct ar8xxx_chip ar8337_chip;
.name = (_n), \
}
#define AR8216_MIB_RXB_ID 14 /* RxGoodByte */
#define AR8216_MIB_TXB_ID 29 /* TxByte */
#define AR8236_MIB_RXB_ID 15 /* RxGoodByte */
#define AR8236_MIB_TXB_ID 31 /* TxByte */
static const struct ar8xxx_mib_desc ar8216_mibs[] = {
MIB_DESC(1, AR8216_STATS_RXBROAD, "RxBroad"),
MIB_DESC(1, AR8216_STATS_RXPAUSE, "RxPause"),
@ -1587,56 +1581,6 @@ ar8xxx_sw_set_flush_port_arl_table(struct switch_dev *dev,
return ret;
}
int
ar8xxx_sw_get_port_stats(struct switch_dev *dev, int port,
struct switch_port_stats *stats)
{
struct ar8xxx_priv *priv = swdev_to_ar8xxx(dev);
u64 *mib_stats;
int ret;
int mib_txb_id, mib_rxb_id;
if (!ar8xxx_has_mib_counters(priv))
return -EOPNOTSUPP;
if (port >= dev->ports)
return -EINVAL;
switch (priv->chip_ver) {
case AR8XXX_VER_AR8216:
mib_txb_id = AR8216_MIB_TXB_ID;
mib_rxb_id = AR8216_MIB_RXB_ID;
break;
case AR8XXX_VER_AR8236:
case AR8XXX_VER_AR8316:
case AR8XXX_VER_AR8327:
case AR8XXX_VER_AR8337:
mib_txb_id = AR8236_MIB_TXB_ID;
mib_rxb_id = AR8236_MIB_RXB_ID;
break;
default:
return -EOPNOTSUPP;
}
mutex_lock(&priv->mib_lock);
ret = ar8xxx_mib_capture(priv);
if (ret)
goto unlock;
ar8xxx_mib_fetch_port_stat(priv, port, false);
mib_stats = &priv->mib_stats[port * priv->chip->num_mibs];
stats->tx_bytes = mib_stats[mib_txb_id];
stats->rx_bytes = mib_stats[mib_rxb_id];
ret = 0;
unlock:
mutex_unlock(&priv->mib_lock);
return ret;
}
static const struct switch_attr ar8xxx_sw_attr_globals[] = {
{
.type = SWITCH_TYPE_INT,
@ -1752,7 +1696,16 @@ static const struct switch_dev_ops ar8xxx_sw_ops = {
.apply_config = ar8xxx_sw_hw_apply,
.reset_switch = ar8xxx_sw_reset_switch,
.get_port_link = ar8xxx_sw_get_port_link,
/* The following op is disabled as it hogs the CPU and degrades performance.
An implementation has been attempted in 4d8a66d but reading MIB data is slow
on ar8xxx switches.
The high CPU load has been traced down to the ar8xxx_reg_wait() call in
ar8xxx_mib_op(), which has to usleep_range() till the MIB busy flag set by
the request to update the MIB counter is cleared. */
#if 0
.get_port_stats = ar8xxx_sw_get_port_stats,
#endif
};
static const struct ar8xxx_chip ar8216_chip = {

3
target/linux/generic/files/drivers/net/phy/ar8216.h
View file

@ -566,9 +566,6 @@ ar8xxx_sw_set_flush_port_arl_table(struct switch_dev *dev,
const struct switch_attr *attr,
struct switch_val *val);
int
ar8xxx_sw_get_port_stats(struct switch_dev *dev, int port,
struct switch_port_stats *stats);
int
ar8216_wait_bit(struct ar8xxx_priv *priv, int reg, u32 mask, u32 val);
static inline struct ar8xxx_priv *

9
target/linux/generic/files/drivers/net/phy/ar8327.c
View file

@ -1411,7 +1411,16 @@ static const struct switch_dev_ops ar8327_sw_ops = {
.apply_config = ar8327_sw_hw_apply,
.reset_switch = ar8xxx_sw_reset_switch,
.get_port_link = ar8xxx_sw_get_port_link,
/* The following op is disabled as it hogs the CPU and degrades performance.
An implementation has been attempted in 4d8a66d but reading MIB data is slow
on ar8xxx switches.
The high CPU load has been traced down to the ar8xxx_reg_wait() call in
ar8xxx_mib_op(), which has to usleep_range() till the MIB busy flag set by
the request to update the MIB counter is cleared. */
#if 0
.get_port_stats = ar8xxx_sw_get_port_stats,
#endif
};
const struct ar8xxx_chip ar8327_chip = {