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path: root/drivers/net/ethernet/sfc/ethtool.c
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Diffstat (limited to 'drivers/net/ethernet/sfc/ethtool.c')
-rw-r--r--drivers/net/ethernet/sfc/ethtool.c36
1 files changed, 27 insertions, 9 deletions
diff --git a/drivers/net/ethernet/sfc/ethtool.c b/drivers/net/ethernet/sfc/ethtool.c
index 98b363bb4a75..93f1fb99432d 100644
--- a/drivers/net/ethernet/sfc/ethtool.c
+++ b/drivers/net/ethernet/sfc/ethtool.c
@@ -595,6 +595,20 @@ static int efx_ethtool_nway_reset(struct net_device *net_dev)
* automatically changed too, but otherwise we fail if the two values
* are requested to be different.
*
+ * The hardware does not support a limit on the number of completions
+ * before an IRQ, so we do not use the max_frames fields. We should
+ * report and require that max_frames == (usecs != 0), but this would
+ * invalidate existing user documentation.
+ *
+ * The hardware does not have distinct settings for interrupt
+ * moderation while the previous IRQ is being handled, so we should
+ * not use the 'irq' fields. However, an earlier developer
+ * misunderstood the meaning of the 'irq' fields and the driver did
+ * not support the standard fields. To avoid invalidating existing
+ * user documentation, we report and accept changes through either the
+ * standard or 'irq' fields. If both are changed at the same time, we
+ * prefer the standard field.
+ *
* We implement adaptive IRQ moderation, but use a different algorithm
* from that assumed in the definition of struct ethtool_coalesce.
* Therefore we do not use any of the adaptive moderation parameters
@@ -610,7 +624,9 @@ static int efx_ethtool_get_coalesce(struct net_device *net_dev,
efx_get_irq_moderation(efx, &tx_usecs, &rx_usecs, &rx_adaptive);
+ coalesce->tx_coalesce_usecs = tx_usecs;
coalesce->tx_coalesce_usecs_irq = tx_usecs;
+ coalesce->rx_coalesce_usecs = rx_usecs;
coalesce->rx_coalesce_usecs_irq = rx_usecs;
coalesce->use_adaptive_rx_coalesce = rx_adaptive;
@@ -629,22 +645,24 @@ static int efx_ethtool_set_coalesce(struct net_device *net_dev,
if (coalesce->use_adaptive_tx_coalesce)
return -EINVAL;
- if (coalesce->rx_coalesce_usecs || coalesce->tx_coalesce_usecs) {
- netif_err(efx, drv, efx->net_dev, "invalid coalescing setting. "
- "Only rx/tx_coalesce_usecs_irq are supported\n");
- return -EINVAL;
- }
-
efx_get_irq_moderation(efx, &tx_usecs, &rx_usecs, &adaptive);
- rx_usecs = coalesce->rx_coalesce_usecs_irq;
+ if (coalesce->rx_coalesce_usecs != rx_usecs)
+ rx_usecs = coalesce->rx_coalesce_usecs;
+ else
+ rx_usecs = coalesce->rx_coalesce_usecs_irq;
+
adaptive = coalesce->use_adaptive_rx_coalesce;
/* If channels are shared, TX IRQ moderation can be quietly
* overridden unless it is changed from its old value.
*/
- rx_may_override_tx = coalesce->tx_coalesce_usecs_irq == tx_usecs;
- tx_usecs = coalesce->tx_coalesce_usecs_irq;
+ rx_may_override_tx = (coalesce->tx_coalesce_usecs == tx_usecs &&
+ coalesce->tx_coalesce_usecs_irq == tx_usecs);
+ if (coalesce->tx_coalesce_usecs != tx_usecs)
+ tx_usecs = coalesce->tx_coalesce_usecs;
+ else
+ tx_usecs = coalesce->tx_coalesce_usecs_irq;
rc = efx_init_irq_moderation(efx, tx_usecs, rx_usecs, adaptive,
rx_may_override_tx);