[PATCH net-next v8 07/17] net: macb: refuse set_ringparam on EMAC
From: Théo Lebrun
Date: Wed Aug 05 2026 - 13:47:50 EST
EMAC has never supported changing ring sizes: RX is hardcoded to 9 and
TX is the tiniest ring buffer you can imagine.
Make sure the operation fails early rather than silently succeed and
storing values in bp->configured_{rx,tx}_ring_size that are never read
in the EMAC case.
Signed-off-by: Théo Lebrun <theo.lebrun@xxxxxxxxxxx>
---
drivers/net/ethernet/cadence/macb_main.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
index af351d30adab..1476bce77f34 100644
--- a/drivers/net/ethernet/cadence/macb_main.c
+++ b/drivers/net/ethernet/cadence/macb_main.c
@@ -3687,6 +3687,9 @@ static int macb_set_ringparam(struct net_device *netdev,
u32 new_rx_size, new_tx_size;
unsigned int reset = 0;
+ if (bp->caps & MACB_CAPS_MACB_IS_EMAC)
+ return -EOPNOTSUPP;
+
if ((ring->rx_mini_pending) || (ring->rx_jumbo_pending))
return -EINVAL;
--
2.55.0