[PATCH] net: stmmac: xgmac2: disable RBUE in default RX interrupt mask

[muhammad . nazim . amirul . nazle . asmade]

From: Nazim Amirul <muhammad.nazim.amirul.nazle.asmade@xxxxxxxxxx>

Enabling the RX Buffer Unavailable (RBUE) interrupt is counterproductive
and can trigger a MAC interrupt storm under heavy RX pressure. When the
DMA runs out of RX descriptors it fires RBUE continuously until software
refills the ring.

However, RBUE is redundant: the normal RX completion interrupt (RIE)
already triggers NAPI, which processes completed descriptors and refills
the ring, causing the DMA to resume. The RBUE handler itself only sets
handle_rx - the same outcome as RIE.

Remove RBUE from XGMAC_DMA_INT_DEFAULT_EN and XGMAC_DMA_INT_DEFAULT_RX
to prevent the interrupt storm while keeping normal RX handling intact.

Fixes: d6ddfacd95c7 ("net: stmmac: Add DMA related callbacks for XGMAC2")
Signed-off-by: Nazim Amirul <muhammad.nazim.amirul.nazle.asmade@xxxxxxxxxx>
---
 drivers/net/ethernet/stmicro/stmmac/dwxgmac2.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwxgmac2.h b/drivers/net/ethernet/stmicro/stmmac/dwxgmac2.h
index 51943705a2b0..b5fdc253a2f2 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwxgmac2.h
+++ b/drivers/net/ethernet/stmicro/stmmac/dwxgmac2.h
@@ -379,9 +379,9 @@
 #define XGMAC_RIE			BIT(6)
 #define XGMAC_TBUE			BIT(2)
 #define XGMAC_TIE			BIT(0)
-#define XGMAC_DMA_INT_DEFAULT_EN	(XGMAC_NIE | XGMAC_AIE | XGMAC_RBUE | \
+#define XGMAC_DMA_INT_DEFAULT_EN	(XGMAC_NIE | XGMAC_AIE | \
 					XGMAC_RIE | XGMAC_TIE)
-#define XGMAC_DMA_INT_DEFAULT_RX	(XGMAC_RBUE | XGMAC_RIE)
+#define XGMAC_DMA_INT_DEFAULT_RX	(XGMAC_RIE)
 #define XGMAC_DMA_INT_DEFAULT_TX	(XGMAC_TIE)
 #define XGMAC_DMA_CH_Rx_WATCHDOG(x)	(0x0000313c + (0x80 * (x)))
 #define XGMAC_RWT			GENMASK(7, 0)
-- 
2.43.7