Patch "net: stmmac: Limit FIFO size by hardware capability" has been added to the 6.13-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    net: stmmac: Limit FIFO size by hardware capability

to the 6.13-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     net-stmmac-limit-fifo-size-by-hardware-capability.patch
and it can be found in the queue-6.13 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 53935f54c1e3ddf8285668996d7f519011ed90dd
Author: Kunihiko Hayashi <hayashi.kunihiko@xxxxxxxxxxxxx>
Date:   Mon Jan 27 10:38:19 2025 +0900

    net: stmmac: Limit FIFO size by hardware capability
    
    [ Upstream commit 044f2fbaa2725696ecbf1f02ba7ab0a8ccb7e1ae ]
    
    Tx/Rx FIFO size is specified by the parameter "{tx,rx}-fifo-depth" from
    stmmac_platform layer.
    
    However, these values are constrained by upper limits determined by the
    capabilities of each hardware feature. There is a risk that the upper
    bits will be truncated due to the calculation, so it's appropriate to
    limit them to the upper limit values and display a warning message.
    
    This only works if the hardware capability has the upper limit values.
    
    Fixes: e7877f52fd4a ("stmmac: Read tx-fifo-depth and rx-fifo-depth from the devicetree")
    Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@xxxxxxxxxxxxx>
    Reviewed-by: Yanteng Si <si.yanteng@xxxxxxxxx>
    Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 17a5be4f57c8d..1bed3e7629faa 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -7190,6 +7190,21 @@ static int stmmac_hw_init(struct stmmac_priv *priv)
 		priv->plat->tx_queues_to_use = priv->dma_cap.number_tx_queues;
 	}
 
+	if (priv->dma_cap.rx_fifo_size &&
+	    priv->plat->rx_fifo_size > priv->dma_cap.rx_fifo_size) {
+		dev_warn(priv->device,
+			 "Rx FIFO size (%u) exceeds dma capability\n",
+			 priv->plat->rx_fifo_size);
+		priv->plat->rx_fifo_size = priv->dma_cap.rx_fifo_size;
+	}
+	if (priv->dma_cap.tx_fifo_size &&
+	    priv->plat->tx_fifo_size > priv->dma_cap.tx_fifo_size) {
+		dev_warn(priv->device,
+			 "Tx FIFO size (%u) exceeds dma capability\n",
+			 priv->plat->tx_fifo_size);
+		priv->plat->tx_fifo_size = priv->dma_cap.tx_fifo_size;
+	}
+
 	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;