net: dsa: mv88e6xxx: Release mutex between each statistics read
The PTP code needs low latency access to the PTP hardware timestamps.
Reading all the statistics in one go adds a lot of latency to the PTP
code. So take and release the reg_lock mutex for each individual
statistics, allowing the PTP thread jump in between.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/dsa/mv88e6xxx/chip.c b/drivers/net/dsa/mv88e6xxx/chip.c
index af63710..bd5cb8a 100644
--- a/drivers/net/dsa/mv88e6xxx/chip.c
+++ b/drivers/net/dsa/mv88e6xxx/chip.c
@@ -714,9 +714,12 @@ static void mv88e6xxx_stats_get_stats(struct mv88e6xxx_chip *chip, int port,
for (i = 0, j = 0; i < ARRAY_SIZE(mv88e6xxx_hw_stats); i++) {
stat = &mv88e6xxx_hw_stats[i];
if (stat->type & types) {
+ mutex_lock(&chip->reg_lock);
data[j] = _mv88e6xxx_get_ethtool_stat(chip, stat, port,
bank1_select,
histogram);
+ mutex_unlock(&chip->reg_lock);
+
j++;
}
}
@@ -764,14 +767,13 @@ static void mv88e6xxx_get_ethtool_stats(struct dsa_switch *ds, int port,
mutex_lock(&chip->reg_lock);
ret = mv88e6xxx_stats_snapshot(chip, port);
- if (ret < 0) {
- mutex_unlock(&chip->reg_lock);
+ mutex_unlock(&chip->reg_lock);
+
+ if (ret < 0)
return;
- }
mv88e6xxx_get_stats(chip, port, data);
- mutex_unlock(&chip->reg_lock);
}
static int mv88e6xxx_stats_set_histogram(struct mv88e6xxx_chip *chip)