diff options
| author | Eric Dumazet <edumazet@google.com> | 2017-02-24 02:22:43 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-02-26 23:39:43 +0300 |
| commit | 47d3a07528ecbbccf53bc4390d70b4e3d1c04fcf (patch) | |
| tree | 3b76e771fa632c766ec0b4b25a6fdbbb01fa2ce1 /drivers/net/ethernet | |
| parent | 8b1bb92bb6f6f5b05379c39f0e3bbf4f359e9298 (diff) | |
| download | linux-47d3a07528ecbbccf53bc4390d70b4e3d1c04fcf.tar.xz | |
net/mlx4_en: fix overflow in mlx4_en_init_timestamp()
The cited commit makes a great job of finding optimal shift/multiplier
values assuming a 10 seconds wrap around, but forgot to change the
overflow_period computation.
It overflows in cyclecounter_cyc2ns(), and the final result is 804 ms,
which is silly.
Lets simply use 5 seconds, no need to recompute this, given how it is
supposed to work.
Later, we will use a timer instead of a work queue, since the new RX
allocation schem will no longer need mlx4_en_recover_from_oom() and the
service_task firing every 250 ms.
Fixes: 31c128b66e5b ("net/mlx4_en: Choose time-stamping shift value according to HW frequency")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Tariq Toukan <tariqt@mellanox.com>
Cc: Eugenia Emantayev <eugenia@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/ethernet')
| -rw-r--r-- | drivers/net/ethernet/mellanox/mlx4/en_clock.c | 18 | ||||
| -rw-r--r-- | drivers/net/ethernet/mellanox/mlx4/mlx4_en.h | 1 |
2 files changed, 8 insertions, 11 deletions
diff --git a/drivers/net/ethernet/mellanox/mlx4/en_clock.c b/drivers/net/ethernet/mellanox/mlx4/en_clock.c index e7b81a305469..024788549c25 100644 --- a/drivers/net/ethernet/mellanox/mlx4/en_clock.c +++ b/drivers/net/ethernet/mellanox/mlx4/en_clock.c @@ -89,10 +89,17 @@ void mlx4_en_remove_timestamp(struct mlx4_en_dev *mdev) } } +#define MLX4_EN_WRAP_AROUND_SEC 10UL +/* By scheduling the overflow check every 5 seconds, we have a reasonably + * good chance we wont miss a wrap around. + * TOTO: Use a timer instead of a work queue to increase the guarantee. + */ +#define MLX4_EN_OVERFLOW_PERIOD (MLX4_EN_WRAP_AROUND_SEC * HZ / 2) + void mlx4_en_ptp_overflow_check(struct mlx4_en_dev *mdev) { bool timeout = time_is_before_jiffies(mdev->last_overflow_check + - mdev->overflow_period); + MLX4_EN_OVERFLOW_PERIOD); unsigned long flags; if (timeout) { @@ -237,7 +244,6 @@ static const struct ptp_clock_info mlx4_en_ptp_clock_info = { .enable = mlx4_en_phc_enable, }; -#define MLX4_EN_WRAP_AROUND_SEC 10ULL /* This function calculates the max shift that enables the user range * of MLX4_EN_WRAP_AROUND_SEC values in the cycles register. @@ -258,7 +264,6 @@ void mlx4_en_init_timestamp(struct mlx4_en_dev *mdev) { struct mlx4_dev *dev = mdev->dev; unsigned long flags; - u64 ns, zero = 0; /* mlx4_en_init_timestamp is called for each netdev. * mdev->ptp_clock is common for all ports, skip initialization if @@ -282,13 +287,6 @@ void mlx4_en_init_timestamp(struct mlx4_en_dev *mdev) ktime_to_ns(ktime_get_real())); write_sequnlock_irqrestore(&mdev->clock_lock, flags); - /* Calculate period in seconds to call the overflow watchdog - to make - * sure counter is checked at least once every wrap around. - */ - ns = cyclecounter_cyc2ns(&mdev->cycles, mdev->cycles.mask, zero, &zero); - do_div(ns, NSEC_PER_SEC / 2 / HZ); - mdev->overflow_period = ns; - /* Configure the PHC */ mdev->ptp_clock_info = mlx4_en_ptp_clock_info; snprintf(mdev->ptp_clock_info.name, 16, "mlx4 ptp"); diff --git a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h index 4941b692e947..3629ce11a68b 100644 --- a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h +++ b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h @@ -430,7 +430,6 @@ struct mlx4_en_dev { seqlock_t clock_lock; struct timecounter clock; unsigned long last_overflow_check; - unsigned long overflow_period; struct ptp_clock *ptp_clock; struct ptp_clock_info ptp_clock_info; struct notifier_block nb; |