From d64e277b955be4506931802837499b62c8f3968a Mon Sep 17 00:00:00 2001 From: Florian Fainelli Date: Mon, 21 Sep 2026 15:00:21 -0700 Subject: [PATCH] net: bcmgenet: mask DMA_TIMEOUT_MASK when reading DMA_RING0_TIMEOUT bcmgenet_get_coalesce() reads DMA_RING0_TIMEOUT to calculate rx_coalesce_usecs without masking out bits outside DMA_TIMEOUT_MASK (16 bits). If upper bits are non-zero or contain status/flags, the computed value of rx_coalesce_usecs returned to userspace via ethtool becomes corrupted. Mask the register read with DMA_TIMEOUT_MASK before computing the timeout in microseconds. Fixes: 4a29645bfe6c ("net: bcmgenet: Implement RX coalescing control knobs") Reviewed-by: Nicolai Buchwitz Signed-off-by: Florian Fainelli Link: https://patch.msgid.link/20260921220021.281418-6-florian.fainelli@broadcom.com Signed-off-by: Jakub Kicinski --- drivers/net/ethernet/broadcom/genet/bcmgenet.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/net/ethernet/broadcom/genet/bcmgenet.c b/drivers/net/ethernet/broadcom/genet/bcmgenet.c index 011376a1678a..21668e41b696 100644 --- a/drivers/net/ethernet/broadcom/genet/bcmgenet.c +++ b/drivers/net/ethernet/broadcom/genet/bcmgenet.c @@ -852,7 +852,8 @@ static int bcmgenet_get_coalesce(struct net_device *dev, ec->rx_max_coalesced_frames = bcmgenet_rdma_ring_readl(priv, 0, DMA_MBUF_DONE_THRESH); ec->rx_coalesce_usecs = - bcmgenet_rdma_readl(priv, DMA_RING0_TIMEOUT) * 8192 / 1000; + (bcmgenet_rdma_readl(priv, DMA_RING0_TIMEOUT) & + DMA_TIMEOUT_MASK) * 8192 / 1000; for (i = 0; i <= priv->hw_params->rx_queues; i++) { ring = &priv->rx_rings[i];