Loongson's DWMAC device may take nearly two seconds to complete DMA reset,
however, the default waiting time for reset is 200 milliseconds.
Therefore, the following error message may appear:

[14.427169] dwmac-loongson-pci 0000:00:03.2: Failed to reset the dma

Fixes: 803fc61df261 ("net: stmmac: dwmac-loongson: Add Loongson Multi-channels GMAC support")
Cc: stable@vger.kernel.org
Signed-off-by: Qunqin Zhao <zhaoqunqin@loongson.cn>
Reviewed-by: Huacai Chen <chenhuacai@loongson.cn>
---
v3: Added "Cc: stable@vger.kernel.org" tag.
    Added error message to commit message.

v2: Added comments. Changed callback name to loongson_dwmac_fix_reset.

 .../net/ethernet/stmicro/stmmac/dwmac-loongson.c   | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-loongson.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-loongson.c
index bfe6e2d631bd..f5acfb7d4ff6 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-loongson.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-loongson.c
@@ -516,6 +516,19 @@ static int loongson_dwmac_acpi_config(struct pci_dev *pdev,
 	return 0;
 }
 
+/* Loongson's DWMAC device may take nearly two seconds to complete DMA reset */
+static int loongson_dwmac_fix_reset(void *priv, void __iomem *ioaddr)
+{
+	u32 value = readl(ioaddr + DMA_BUS_MODE);
+
+	value |= DMA_BUS_MODE_SFT_RESET;
+	writel(value, ioaddr + DMA_BUS_MODE);
+
+	return readl_poll_timeout(ioaddr + DMA_BUS_MODE, value,
+				  !(value & DMA_BUS_MODE_SFT_RESET),
+				  10000, 2000000);
+}
+
 static int loongson_dwmac_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 {
 	struct plat_stmmacenet_data *plat;
@@ -566,6 +579,7 @@ static int loongson_dwmac_probe(struct pci_dev *pdev, const struct pci_device_id
 
 	plat->bsp_priv = ld;
 	plat->setup = loongson_dwmac_setup;
+	plat->fix_soc_reset = loongson_dwmac_fix_reset;
 	ld->dev = &pdev->dev;
 	ld->loongson_id = readl(res.addr + GMAC_VERSION) & 0xff;
 

base-commit: a64dcfb451e254085a7daee5fe51bf22959d52d3
-- 
2.43.0

在 2/19/25 10:07 AM, Qunqin Zhao 写道:
> Loongson's DWMAC device may take nearly two seconds to complete DMA reset,
> however, the default waiting time for reset is 200 milliseconds.
> Therefore, the following error message may appear:
>
> [14.427169] dwmac-loongson-pci 0000:00:03.2: Failed to reset the dma
>
> Fixes: 803fc61df261 ("net: stmmac: dwmac-loongson: Add Loongson Multi-channels GMAC support")
> Cc: stable@vger.kernel.org
> Signed-off-by: Qunqin Zhao <zhaoqunqin@loongson.cn>
> Reviewed-by: Huacai Chen <chenhuacai@loongson.cn>

Acked-by: Yanteng Si <si.yanteng@linux.dev>


Thanks,

Yanteng

> ---
> v3: Added "Cc: stable@vger.kernel.org" tag.
>      Added error message to commit message.
>
> v2: Added comments. Changed callback name to loongson_dwmac_fix_reset.
>
>   .../net/ethernet/stmicro/stmmac/dwmac-loongson.c   | 14 ++++++++++++++
>   1 file changed, 14 insertions(+)

On 2/18/2025 6:07 PM, Qunqin Zhao wrote:
> Loongson's DWMAC device may take nearly two seconds to complete DMA reset,
> however, the default waiting time for reset is 200 milliseconds.
> Therefore, the following error message may appear:
> 
> [14.427169] dwmac-loongson-pci 0000:00:03.2: Failed to reset the dma
> 
> Fixes: 803fc61df261 ("net: stmmac: dwmac-loongson: Add Loongson Multi-channels GMAC support")
> Cc: stable@vger.kernel.org
> Signed-off-by: Qunqin Zhao <zhaoqunqin@loongson.cn>
> Reviewed-by: Huacai Chen <chenhuacai@loongson.cn>
> ---

Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>