[PATCH 1/2] net: ravb: Always process TX descriptor ring

From: Paul Barker
Date: Tue Mar 26 2024 - 04:38:19 EST


The TX queue should be serviced each time the poll function is called,
even if the full RX work budget has been consumed. This prevents
starvation of the TX queue when RX bandwidth usage is high.

Fixes: a0d2f20650e8 ("Renesas Ethernet AVB PTP clock driver")
Signed-off-by: Paul Barker <paul.barker.ct@xxxxxxxxxxxxxx>
---
drivers/net/ethernet/renesas/ravb_main.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
index d1be030c8848..4f98e4e2badb 100644
--- a/drivers/net/ethernet/renesas/ravb_main.c
+++ b/drivers/net/ethernet/renesas/ravb_main.c
@@ -1324,12 +1324,12 @@ static int ravb_poll(struct napi_struct *napi, int budget)
int q = napi - priv->napi;
int mask = BIT(q);
int quota = budget;
+ bool rearm = true;

/* Processing RX Descriptor Ring */
/* Clear RX interrupt */
ravb_write(ndev, ~(mask | RIS0_RESERVED), RIS0);
- if (ravb_rx(ndev, &quota, q))
- goto out;
+ rearm = !ravb_rx(ndev, &quota, q);

/* Processing TX Descriptor Ring */
spin_lock_irqsave(&priv->lock, flags);
@@ -1339,6 +1339,9 @@ static int ravb_poll(struct napi_struct *napi, int budget)
netif_wake_subqueue(ndev, q);
spin_unlock_irqrestore(&priv->lock, flags);

+ if (!rearm)
+ goto out;
+
napi_complete(napi);

/* Re-enable RX/TX interrupts */

base-commit: 4cece764965020c22cff7665b18a012006359095
--
2.44.0