[PATCH net-next 11/11] bnxt_en: Allow statistics DMA to be configurable using ethtool -C.

[Michael Chan]

The allowable range is 0.25 seconds to 1 second interval.  Default is
1 second.

Signed-off-by: Michael Chan <michael.c...@broadcom.com>
---
 drivers/net/ethernet/broadcom/bnxt/bnxt.c         |  4 +++-
 drivers/net/ethernet/broadcom/bnxt/bnxt.h         |  5 +++++
 drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c | 25 +++++++++++++++++++++--
 3 files changed, 31 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c 
b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
index 18be62b..70b148a 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
@@ -3952,7 +3952,7 @@ static int bnxt_hwrm_stat_ctx_alloc(struct bnxt *bp)
 
        bnxt_hwrm_cmd_hdr_init(bp, &req, HWRM_STAT_CTX_ALLOC, -1, -1);
 
-       req.update_period_ms = cpu_to_le32(1000);
+       req.update_period_ms = cpu_to_le32(bp->stats_coal_ticks / 1000);
 
        mutex_lock(&bp->hwrm_cmd_lock);
        for (i = 0; i < bp->cp_nr_rings; i++) {
@@ -5994,6 +5994,8 @@ static int bnxt_init_board(struct pci_dev *pdev, struct 
net_device *dev)
        bp->tx_coal_ticks_irq = 2;
        bp->tx_coal_bufs_irq = 2;
 
+       bp->stats_coal_ticks = BNXT_DEF_STATS_COAL_TICKS;
+
        init_timer(&bp->timer);
        bp->timer.data = (unsigned long)bp;
        bp->timer.function = bnxt_timer;
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.h 
b/drivers/net/ethernet/broadcom/bnxt/bnxt.h
index 1d5a3cd..2313e37 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.h
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.h
@@ -1067,6 +1067,11 @@ struct bnxt {
 
 #define BNXT_USEC_TO_COAL_TIMER(x)     ((x) * 25 / 2)
 
+       u32                     stats_coal_ticks;
+#define BNXT_DEF_STATS_COAL_TICKS       1000000
+#define BNXT_MIN_STATS_COAL_TICKS        250000
+#define BNXT_MAX_STATS_COAL_TICKS       1000000
+
        struct work_struct      sp_task;
        unsigned long           sp_event;
 #define BNXT_RX_MASK_SP_EVENT          0
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c 
b/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c
index 33b3135..0f7dd86 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c
@@ -56,6 +56,8 @@ static int bnxt_get_coalesce(struct net_device *dev,
        coal->tx_coalesce_usecs_irq = bp->tx_coal_ticks_irq;
        coal->tx_max_coalesced_frames_irq = bp->tx_coal_bufs_irq;
 
+       coal->stats_block_coalesce_usecs = bp->stats_coal_ticks;
+
        return 0;
 }
 
@@ -63,6 +65,7 @@ static int bnxt_set_coalesce(struct net_device *dev,
                             struct ethtool_coalesce *coal)
 {
        struct bnxt *bp = netdev_priv(dev);
+       bool update_stats = false;
        int rc = 0;
 
        bp->rx_coal_ticks = coal->rx_coalesce_usecs;
@@ -76,8 +79,26 @@ static int bnxt_set_coalesce(struct net_device *dev,
        bp->tx_coal_ticks_irq = coal->tx_coalesce_usecs_irq;
        bp->tx_coal_bufs_irq = coal->tx_max_coalesced_frames_irq;
 
-       if (netif_running(dev))
-               rc = bnxt_hwrm_set_coal(bp);
+       if (bp->stats_coal_ticks != coal->stats_block_coalesce_usecs) {
+               u32 stats_ticks = coal->stats_block_coalesce_usecs;
+
+               stats_ticks = clamp_t(u32, stats_ticks,
+                                     BNXT_MIN_STATS_COAL_TICKS,
+                                     BNXT_MAX_STATS_COAL_TICKS);
+               stats_ticks = rounddown(stats_ticks, BNXT_MIN_STATS_COAL_TICKS);
+               bp->stats_coal_ticks = stats_ticks;
+               update_stats = true;
+       }
+
+       if (netif_running(dev)) {
+               if (update_stats) {
+                       rc = bnxt_close_nic(bp, true, false);
+                       if (!rc)
+                               rc = bnxt_open_nic(bp, true, false);
+               } else {
+                       rc = bnxt_hwrm_set_coal(bp);
+               }
+       }
 
        return rc;
 }
-- 
1.8.3.1