diff options
| author | Jesse Brandeburg <jesse.brandeburg@intel.com> | 2015-09-28 14:16:52 -0400 |
|---|---|---|
| committer | Jeff Kirsher <jeffrey.t.kirsher@intel.com> | 2015-10-19 15:34:30 -0700 |
| commit | 51cc6d9fccde27310b7dfba2be268ff5b8dcf52d (patch) | |
| tree | 3e66b4fba7e5258e25bfd20d63c2610866d3565d /drivers/net/ethernet/intel/i40e | |
| parent | 8f5e39ce9214888464d34ef7949e56bdc999b46c (diff) | |
i40e/i40evf: fix bug in throttle rate math
The driver was using a value expressed in 2us increments
for the divisor to figure out our bytes/usec values.
Fix the usecs variable to contain a value in microseconds.
Change-ID: I5c20493103c295d6f201947bb908add7040b7c41
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Diffstat (limited to 'drivers/net/ethernet/intel/i40e')
| -rw-r--r-- | drivers/net/ethernet/intel/i40e/i40e_txrx.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.c b/drivers/net/ethernet/intel/i40e/i40e_txrx.c index 889d25d6fde2..c96e581cc2b7 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c +++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c @@ -830,6 +830,7 @@ static bool i40e_set_new_dynamic_itr(struct i40e_ring_container *rc) enum i40e_latency_range new_latency_range = rc->latency_range; u32 new_itr = rc->itr; int bytes_per_int; + int usecs; if (rc->total_packets == 0 || !rc->itr) return false; @@ -838,8 +839,14 @@ static bool i40e_set_new_dynamic_itr(struct i40e_ring_container *rc) * 0-10MB/s lowest (100000 ints/s) * 10-20MB/s low (20000 ints/s) * 20-1249MB/s bulk (8000 ints/s) + * + * The math works out because the divisor is in 10^(-6) which + * turns the bytes/us input value into MB/s values, but + * make sure to use usecs, as the register values written + * are in 2 usec increments in the ITR registers. */ - bytes_per_int = rc->total_bytes / rc->itr; + usecs = (rc->itr << 1); + bytes_per_int = rc->total_bytes / usecs; switch (new_latency_range) { case I40E_LOWEST_LATENCY: if (bytes_per_int > 10) |