From: Elad Kanfi <elad...@mellanox.com>
The tx interrupt is of edge type, and in case such interrupt is triggered
while it is masked it will not be handled even after tx interrupts are
re-enabled in the end of NAPI poll.
This will cause tx network to stop in the following scenario:
* Rx is being handled, hence interrupts are masked.
* Tx interrupt is triggered after checking if there is some tx to handle
and before re-enabling the interrupts.
In this situation only rx transaction will release tx requests.
In order to handle the tx that was missed( if there was one ),
a NAPI reschdule was added after enabling the interrupts.
Signed-off-by: Elad Kanfi <elad...@mellanox.com>
Acked-by: Noam Camus <noa...@mellanox.com>
Acked-by: Gilad Ben-Yossef <gila...@mellanox.com>
---
drivers/net/ethernet/ezchip/nps_enet.c | 15 +++++++++++++++
1 files changed, 15 insertions(+), 0 deletions(-)
diff --git a/drivers/net/ethernet/ezchip/nps_enet.c
b/drivers/net/ethernet/ezchip/nps_enet.c
index 25ac2de..085f912 100644
--- a/drivers/net/ethernet/ezchip/nps_enet.c
+++ b/drivers/net/ethernet/ezchip/nps_enet.c
@@ -183,6 +183,9 @@ static int nps_enet_poll(struct napi_struct *napi, int
budget)
work_done = nps_enet_rx_handler(ndev);
if (work_done < budget) {
u32 buf_int_enable_value = 0;
+ u32 tx_ctrl_value = nps_enet_reg_get(priv, NPS_ENET_REG_TX_CTL);
+ u32 tx_ctrl_ct =
+ (tx_ctrl_value & TX_CTL_CT_MASK) >> TX_CTL_CT_SHIFT;
napi_complete(napi);
@@ -192,6 +195,18 @@ static int nps_enet_poll(struct napi_struct *napi, int
budget)
nps_enet_reg_set(priv, NPS_ENET_REG_BUF_INT_ENABLE,
buf_int_enable_value);
+
+ /* in case we will get a tx interrupt while interrupts
+ * are masked, we will lose it since the tx is edge interrupt.
+ * specifically, while executing the code section above,
+ * between nps_enet_tx_handler and the interrupts enable, all
+ * tx requests will be stuck until we will get an rx interrupt.
+ * the two code lines below will solve this situation by
+ * re-adding ourselves to the poll list.
+ */
+
+ if (priv->tx_skb && !tx_ctrl_ct)
+ napi_reschedule(napi);
}
return work_done;
--
1.7.1
