Thanks a lot for your review.

From: Philipp Zabel <p.zabel@pengutronix.de>
Sent: Wednesday, November 3, 2021 8:10 PM
To: Wells Lu <wellslutw@gmail.com>; davem@davemloft.net;
kuba@kernel.org; robh+dt@kernel.org; netdev@vger.kernel.org;
devicetree@vger.kernel.org; linux-kernel@vger.kernel.org
Cc: Wells Lu 呂芳騰 <redacted>
Subject: Re: [PATCH 2/2] net: ethernet: Add driver for Sunplus SP7021

On Wed, 2021-11-03 at 19:02 +0800, Wells Lu wrote:
[...]

quoted

diff --git a/drivers/net/ethernet/sunplus/l2sw_driver.c

b/drivers/net/ethernet/sunplus/l2sw_driver.c
new file mode 100644
index 0000000..3dfd0dd

--- /dev/null
+++ b/drivers/net/ethernet/sunplus/l2sw_driver.c

@@ -0,0 +1,779 @@

[...]

quoted

+static int l2sw_probe(struct platform_device *pdev) {
+	struct l2sw_common *comm;
+	struct resource *r_mem;
+	struct net_device *net_dev, *net_dev2;
+	struct l2sw_mac *mac, *mac2;
+	u32 mode;
+	int ret = 0;
+	int rc;
+
+	if (platform_get_drvdata(pdev))
+		return -ENODEV;
+
+	// Allocate memory for l2sw 'common' area.
+	comm = kmalloc(sizeof(*comm), GFP_KERNEL);

I'd use devm_kzalloc() here for initialization and to simplify the cleanup
path.

I'll replace kmalloc() with devm_kzalloc() and remove the kfree(...) in
cleanup path (platform remove) in PATCH v2.

quoted

+	if (!comm)
+		return -ENOMEM;
+	pr_debug(" comm = %p\n", comm);

What is this useful for?

'pr_debug(" comm = %p\n", comm);' is for early-stage debug.
I'll remove the line in PATCH v2.

quoted

+	memset(comm, '\0', sizeof(struct l2sw_common));

Not needed with kzalloc, See above.

Yes, I'll remove the line 'memset(...);' as devm_kzalloc() will be used in PATCH v2.

[...]

quoted

+	// Get memory resoruce 0 from dts.
+	r_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (r_mem) {
+		pr_debug(" res->name = \"%s\", r_mem->start = %pa\n",

r_mem->name, &r_mem->start);

quoted

+		if (l2sw_reg_base_set(devm_ioremap(&pdev->dev, r_mem->start,
+						   (r_mem->end - r_mem->start + 1))) != 0) {
+			pr_err(" ioremap failed!\n");
+			ret = -ENOMEM;
+			goto out_free_comm;
+		}
+	} else {
+		pr_err(" No MEM resource 0 found!\n");
+		ret = -ENXIO;
+		goto out_free_comm;
+	}
+
+	// Get memory resoruce 1 from dts.
+	r_mem = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+	if (r_mem) {
+		pr_debug(" res->name = \"%s\", r_mem->start = %pa\n",

r_mem->name, &r_mem->start);

quoted

+		if (moon5_reg_base_set(devm_ioremap(&pdev->dev,

r_mem->start,

quoted

+						    (r_mem->end - r_mem->start + 1))) != 0) {
+			pr_err(" ioremap failed!\n");
+			ret = -ENOMEM;
+			goto out_free_comm;
+		}
+	} else {
+		pr_err(" No MEM resource 1 found!\n");
+		ret = -ENXIO;
+		goto out_free_comm;
+	}

Using devm_ioremap_resource() would simplify both a lot.

Yes, I'll replace devm_ioremap() with devm_ioremap_resource() in PATCH v2.

[...]

quoted

+	comm->rstc = devm_reset_control_get(&pdev->dev, NULL);

Please use devm_reset_control_get_exclusive().

Yes, I'll replace devm_reset_control_get() with devm_reset_control_get_exclusive() in PATCH v2.

quoted

+	if (IS_ERR(comm->rstc)) {
+		dev_err(&pdev->dev, "Failed to retrieve reset controller!\n");
+		ret = PTR_ERR(comm->rstc);
+		goto out_free_comm;
+	}
+
+	// Enable clock.
+	clk_prepare_enable(comm->clk);
+	udelay(1);
+
+	ret = reset_control_assert(comm->rstc);

No need to assign to ret if you ignore it anyway.

Ok, I'll remove 'ret =' in PATCH v2

quoted

+	udelay(1);
+	ret = reset_control_deassert(comm->rstc);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to deassert reset line (err = %d)!\n",

ret);

quoted

+		ret = -ENODEV;
+		goto out_free_comm;
+	}
+	udelay(1);

regards
Philipp

Best regards,
Wells