net: ravb: Always process TX descriptor ring

[ Upstream commit 596a4254915f94c927217fe09c33a6828f33fb25 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
index b87e9252ea176e73f5d169eaac4d2da23366ca47..14595d23b1903b9f6ba07605209f8b48b0fe0dad 100644 (file)
--- a/drivers/net/ethernet/renesas/ravb_main.c
+++ b/drivers/net/ethernet/renesas/ravb_main.c
@@ -1292,12 +1292,12 @@ 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);
@@ -1307,6 +1307,9 @@ 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 */