ixgbe: Limit SFP polling rate

Reduce the frequency of polling for SFP modules. Because the
service task sometimes runs at high rates, we can poll for
SFPs too often. When an SFP is not present, the I2C timeouts
that result are very costly. So, prevent SFP polling from
being done more than once every two seconds. To reduce latency,
the poll time is cleared in a couple of cases to permit the
next service task execution to poll the SFP module.

Signed-off-by: Mark Rustad <mark.d.rustad@intel.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe.h b/drivers/net/ethernet/intel/ixgbe/ixgbe.h
index a699c991ad2c..dda0f678339a 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe.h
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe.h
@@ -594,6 +594,7 @@ struct ixgbe_mac_addr {
 
 /* default to trying for four seconds */
 #define IXGBE_TRY_LINK_TIMEOUT (4 * HZ)
+#define IXGBE_SFP_POLL_JIFFIES (2 * HZ)	/* SFP poll every 2 seconds */
 
 /* board specific private data structure */
 struct ixgbe_adapter {
@@ -707,6 +708,7 @@ struct ixgbe_adapter {
 
 	u32 link_speed;
 	bool link_up;
+	unsigned long sfp_poll_time;
 	unsigned long link_check_timeout;
 
 	struct timer_list service_timer;