From: Huacai Chen chenhuacai@loongson.cn
[ Upstream commit 8dbf0c7556454b52af91bae305ca71500c31495c ]
Now for dwmac-loongson {tx,rx}_fifo_size are uninitialised, which means zero. This means dwmac-loongson doesn't support changing MTU because in stmmac_change_mtu() it requires the fifo size be no less than MTU. Thus, set the correct tx_fifo_size and rx_fifo_size for it (16KB multiplied by queue counts).
Here {tx,rx}_fifo_size is initialised with the initial value (also the maximum value) of {tx,rx}_queues_to_use. So it will keep as 16KB if we don't change the queue count, and will be larger than 16KB if we change (decrease) the queue count. However stmmac_change_mtu() still work well with current logic (MTU cannot be larger than 16KB for stmmac).
Note: the Fixes tag picked here is the oldest commit and key commit of the dwmac-loongson series "stmmac: Add Loongson platform support".
Acked-by: Yanteng Si si.yanteng@linux.dev Reviewed-by: Simon Horman horms@kernel.org Signed-off-by: Chong Qiao qiaochong@loongson.cn Signed-off-by: Huacai Chen chenhuacai@loongson.cn Link: https://patch.msgid.link/20250210134328.2755328-1-chenhuacai@loongson.cn Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/stmicro/stmmac/dwmac-loongson.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-loongson.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-loongson.c index ab7c2750c1042..702ea5a00b56d 100644 --- a/drivers/net/ethernet/stmicro/stmmac/dwmac-loongson.c +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-loongson.c @@ -590,6 +590,9 @@ static int loongson_dwmac_probe(struct pci_dev *pdev, const struct pci_device_id if (ret) goto err_disable_device;
+ plat->tx_fifo_size = SZ_16K * plat->tx_queues_to_use; + plat->rx_fifo_size = SZ_16K * plat->rx_queues_to_use; + if (dev_of_node(&pdev->dev)) ret = loongson_dwmac_dt_config(pdev, plat, &res); else