net: stmmac: Limit the number of MTL queues to hardware capability

[ Upstream commit f5fb35a3d6b36d378b2e2ecbfb9caa337d5428e6 ]

The number of MTL queues to use is specified by the parameter
"snps,{tx,rx}-queues-to-use" from stmmac_platform layer.

However, the maximum numbers of queues are constrained by upper limits
determined by the capability of each hardware feature. It's appropriate
to limit the values not to exceed the upper limit values and display
a warning message.

This only works if the hardware capability has the upper limit values.

Fixes: d976a525c371 ("net: stmmac: multiple queues dt configuration")
Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
Reviewed-by: Yanteng Si <si.yanteng@linux.dev>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index c81ea8cdfe6eb8f8cfe492a0c486d26b6b87551b..17a5be4f57c8d03cd9c218555cba960d7bfc2cd9 100644 (file)
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -7175,6 +7175,21 @@ static int stmmac_hw_init(struct stmmac_priv *priv)
        if (priv->dma_cap.tsoen)
                dev_info(priv->device, "TSO supported\n");
 
+       if (priv->dma_cap.number_rx_queues &&
+           priv->plat->rx_queues_to_use > priv->dma_cap.number_rx_queues) {
+               dev_warn(priv->device,
+                        "Number of Rx queues (%u) exceeds dma capability\n",
+                        priv->plat->rx_queues_to_use);
+               priv->plat->rx_queues_to_use = priv->dma_cap.number_rx_queues;
+       }
+       if (priv->dma_cap.number_tx_queues &&
+           priv->plat->tx_queues_to_use > priv->dma_cap.number_tx_queues) {
+               dev_warn(priv->device,
+                        "Number of Tx queues (%u) exceeds dma capability\n",
+                        priv->plat->tx_queues_to_use);
+               priv->plat->tx_queues_to_use = priv->dma_cap.number_tx_queues;
+       }
+
        priv->hw->vlan_fail_q_en =
                (priv->plat->flags & STMMAC_FLAG_VLAN_FAIL_Q_EN);
        priv->hw->vlan_fail_q = priv->plat->vlan_fail_q;