sfc: tidy up PTP synchronize function efx_ptp_process_times()

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

1 files changed, 7 insertions, 28 deletions

diff --git a/drivers/net/ethernet/sfc/ptp.c b/drivers/net/ethernet/sfc/ptp.c
index 2b40cbd6667b..d1858c0e0827 100644
--- a/drivers/net/ethernet/sfc/ptp.c
+++ b/drivers/net/ethernet/sfc/ptp.c
@@ -432,13 +432,10 @@ static int efx_ptp_process_times(struct efx_nic *efx, u8 *synch_buf,
         unsigned number_readings = (response_length /
                                MC_CMD_PTP_OUT_SYNCHRONIZE_TIMESET_LEN);
         unsigned i;
-        unsigned min;
-        unsigned min_set = 0;
         unsigned total;
         unsigned ngood = 0;
         unsigned last_good = 0;
         struct efx_ptp_data *ptp = efx->ptp_data;
-        bool min_valid = false;
         u32 last_sec;
         u32 start_sec;
         struct timespec delta;
@@ -446,35 +443,17 @@ static int efx_ptp_process_times(struct efx_nic *efx, u8 *synch_buf,
         if (number_readings == 0)
                 return -EAGAIN;
 
-        /* Find minimum value in this set of results, discarding clearly
-         * erroneous results.
+        /* Read the set of results and increment stats for any results that
+         * appera to be erroneous.
          */
         for (i = 0; i < number_readings; i++) {
                 efx_ptp_read_timeset(synch_buf, &ptp->timeset[i]);
                 synch_buf += MC_CMD_PTP_OUT_SYNCHRONIZE_TIMESET_LEN;
-                if (ptp->timeset[i].window > SYNCHRONISATION_GRANULARITY_NS) {
-                        if (min_valid) {
-                                if (ptp->timeset[i].window < min_set)
-                                        min_set = ptp->timeset[i].window;
-                        } else {
-                                min_valid = true;
-                                min_set = ptp->timeset[i].window;
-                        }
-                }
-        }
-
-        if (min_valid) {
-                if (ptp->base_sync_valid && (min_set > ptp->base_sync_ns))
-                        min = ptp->base_sync_ns;
-                else
-                        min = min_set;
-        } else {
-                min = SYNCHRONISATION_GRANULARITY_NS;
         }
 
-        /* Discard excessively long synchronise durations.  The MC times
-         * when it finishes reading the host time so the corrected window
-         * time should be fairly constant for a given platform.
+        /* Find the last good host-MC synchronization result. The MC times
+         * when it finishes reading the host time so the corrected window time
+         * should be fairly constant for a given platform.
          */
         total = 0;
         for (i = 0; i < number_readings; i++)
@@ -492,8 +471,8 @@ static int efx_ptp_process_times(struct efx_nic *efx, u8 *synch_buf,
 
         if (ngood == 0) {
                 netif_warn(efx, drv, efx->net_dev,
-                           "PTP no suitable synchronisations %dns %dns\n",
-                           ptp->base_sync_ns, min_set);
+                           "PTP no suitable synchronisations %dns\n",
+                           ptp->base_sync_ns);
                 return -EAGAIN;
         }