net: ravb: Always process TX descriptor ring

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: c156633f1353 ("Renesas Ethernet AVB driver proper")
Signed-off-by: Paul Barker <paul.barker.ct@bp.renesas.com>
Reviewed-by: Sergey Shtylyov <s.shtylyov@omp.ru>
Link: https://lore.kernel.org/r/20240402145305.82148-1-paul.barker.ct@bp.renesas.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
index d1be030c88483ae217a84d9047d883dbf6cfad54..48803050abdbf32fb432d9df65e6c7eef7a7098d 100644 (file)
--- 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 unmask;
 
        /* Processing RX Descriptor Ring */
        /* Clear RX interrupt */
        ravb_write(ndev, ~(mask | RIS0_RESERVED), RIS0);
-       if (ravb_rx(ndev, &quota, q))
-               goto out;
+       unmask = !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 (!unmask)
+               goto out;
+
        napi_complete(napi);
 
        /* Re-enable RX/TX interrupts */