net: stmmac: dwmac-loongson: Add fix_soc_reset() callback

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>
Acked-by: Yanteng Si <si.yanteng@linux.dev>
Link: https://patch.msgid.link/20250219020701.15139-1-zhaoqunqin@loongson.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-loongson.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-loongson.c
index bfe6e2d631bdf53e71d182e1759d2e413f8a2348..f5acfb7d4ff655088ab4a9795726e82a4c7b0cd4 100644 (file)
--- 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;