[PATCH v4 1/3] soc: imx8m: Probe the SoC driver as platform driver

[PATCH v4 1/3] soc: imx8m: Probe the SoC driver as platform driver

[Marek Vasut]

With driver_async_probe=* on kernel command line, the following trace is
produced because on i.MX8M Plus hardware because the soc-imx8m.c driver
calls of_clk_get_by_name() which returns -EPROBE_DEFER because the clock
driver is not yet probed. This was not detected during regular testing
without driver_async_probe.

Convert the SoC code to platform driver and instantiate a platform device
in its current device_initcall() to probe the platform driver. Rework
.soc_revision callback to always return valid error code and return SoC
revision via parameter. This way, if anything in the .soc_revision callback
return -EPROBE_DEFER, it gets propagated to .probe and the .probe will get
retried later.

"
------------[ cut here ]------------
WARNING: CPU: 1 PID: 1 at drivers/soc/imx/soc-imx8m.c:115 imx8mm_soc_revision+0xdc/0x180
CPU: 1 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.11.0-next-20240924-00002-g2062bb554dea #603
Hardware name: DH electronics i.MX8M Plus DHCOM Premium Developer Kit (3) (DT)
pstate: 20000005 (nzCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : imx8mm_soc_revision+0xdc/0x180
lr : imx8mm_soc_revision+0xd0/0x180
sp : ffff8000821fbcc0
x29: ffff8000821fbce0 x28: 0000000000000000 x27: ffff800081810120
x26: ffff8000818a9970 x25: 0000000000000006 x24: 0000000000824311
x23: ffff8000817f42c8 x22: ffff0000df8be210 x21: fffffffffffffdfb
x20: ffff800082780000 x19: 0000000000000001 x18: ffffffffffffffff
x17: ffff800081fff418 x16: ffff8000823e1000 x15: ffff0000c03b65e8
x14: ffff0000c00051b0 x13: ffff800082790000 x12: 0000000000000801
x11: ffff80008278ffff x10: ffff80008209d3a6 x9 : ffff80008062e95c
x8 : ffff8000821fb9a0 x7 : 0000000000000000 x6 : 00000000000080e3
x5 : ffff0000df8c03d8 x4 : 0000000000000000 x3 : 0000000000000000
x2 : 0000000000000000 x1 : fffffffffffffdfb x0 : fffffffffffffdfb
Call trace:
 imx8mm_soc_revision+0xdc/0x180
 imx8_soc_init+0xb0/0x1e0
 do_one_initcall+0x94/0x1a8
 kernel_init_freeable+0x240/0x2a8
 kernel_init+0x28/0x140
 ret_from_fork+0x10/0x20
---[ end trace 0000000000000000 ]---
SoC: i.MX8MP revision 1.1
"

Signed-off-by: Marek Vasut <marex@denx.de>
---
Cc: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Fabio Estevam <festevam@gmail.com>
Cc: Jeff Johnson <quic_jjohnson@quicinc.com>
Cc: Neil Armstrong <neil.armstrong@linaro.org>
Cc: Pengutronix Kernel Team <kernel@pengutronix.de>
Cc: Saravana Kannan <saravanak@google.com>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: imx@lists.linux.dev
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
---
V2: Use the platform device approach instead of late_initcall
V3: Do not register imx8m_soc_driver on non-iMX8M hardware
V4: No change
---
 drivers/soc/imx/soc-imx8m.c | 107 ++++++++++++++++++++++++++++--------
 1 file changed, 85 insertions(+), 22 deletions(-)

diff --git a/drivers/soc/imx/soc-imx8m.c b/drivers/soc/imx/soc-imx8m.c
index fe111bae38c8e..5ea8887828c06 100644
--- a/drivers/soc/imx/soc-imx8m.c
+++ b/drivers/soc/imx/soc-imx8m.c
@@ -30,7 +30,7 @@
 
 struct imx8_soc_data {
 	char *name;
-	u32 (*soc_revision)(void);
+	int (*soc_revision)(u32 *socrev);
 };
 
 static u64 soc_uid;
@@ -51,24 +51,29 @@ static u32 imx8mq_soc_revision_from_atf(void)
 static inline u32 imx8mq_soc_revision_from_atf(void) { return 0; };
 #endif
 
-static u32 __init imx8mq_soc_revision(void)
+static int imx8mq_soc_revision(u32 *socrev)
 {
 	struct device_node *np;
 	void __iomem *ocotp_base;
 	u32 magic;
 	u32 rev;
 	struct clk *clk;
+	int ret;
 
 	np = of_find_compatible_node(NULL, NULL, "fsl,imx8mq-ocotp");
 	if (!np)
-		return 0;
+		return -EINVAL;
 
 	ocotp_base = of_iomap(np, 0);
-	WARN_ON(!ocotp_base);
+	if (!ocotp_base) {
+		ret = -EINVAL;
+		goto err_iomap;
+	}
+
 	clk = of_clk_get_by_name(np, NULL);
 	if (IS_ERR(clk)) {
-		WARN_ON(IS_ERR(clk));
-		return 0;
+		ret = PTR_ERR(clk);
+		goto err_clk;
 	}
 
 	clk_prepare_enable(clk);
@@ -88,32 +93,45 @@ static u32 __init imx8mq_soc_revision(void)
 	soc_uid <<= 32;
 	soc_uid |= readl_relaxed(ocotp_base + OCOTP_UID_LOW);
 
+	*socrev = rev;
+
 	clk_disable_unprepare(clk);
 	clk_put(clk);
 	iounmap(ocotp_base);
 	of_node_put(np);
 
-	return rev;
+	return 0;
+
+err_clk:
+	iounmap(ocotp_base);
+err_iomap:
+	of_node_put(np);
+	return ret;
 }
 
-static void __init imx8mm_soc_uid(void)
+static int imx8mm_soc_uid(void)
 {
 	void __iomem *ocotp_base;
 	struct device_node *np;
 	struct clk *clk;
+	int ret = 0;
 	u32 offset = of_machine_is_compatible("fsl,imx8mp") ?
 		     IMX8MP_OCOTP_UID_OFFSET : 0;
 
 	np = of_find_compatible_node(NULL, NULL, "fsl,imx8mm-ocotp");
 	if (!np)
-		return;
+		return -EINVAL;
 
 	ocotp_base = of_iomap(np, 0);
-	WARN_ON(!ocotp_base);
+	if (!ocotp_base) {
+		ret = -EINVAL;
+		goto err_iomap;
+	}
+
 	clk = of_clk_get_by_name(np, NULL);
 	if (IS_ERR(clk)) {
-		WARN_ON(IS_ERR(clk));
-		return;
+		ret = PTR_ERR(clk);
+		goto err_clk;
 	}
 
 	clk_prepare_enable(clk);
@@ -124,31 +142,41 @@ static void __init imx8mm_soc_uid(void)
 
 	clk_disable_unprepare(clk);
 	clk_put(clk);
+
+err_clk:
 	iounmap(ocotp_base);
+err_iomap:
 	of_node_put(np);
+
+	return ret;
 }
 
-static u32 __init imx8mm_soc_revision(void)
+static int imx8mm_soc_revision(u32 *socrev)
 {
 	struct device_node *np;
 	void __iomem *anatop_base;
-	u32 rev;
+	int ret;
 
 	np = of_find_compatible_node(NULL, NULL, "fsl,imx8mm-anatop");
 	if (!np)
-		return 0;
+		return -EINVAL;
 
 	anatop_base = of_iomap(np, 0);
-	WARN_ON(!anatop_base);
+	if (!anatop_base) {
+		ret = -EINVAL;
+		goto err_iomap;
+	}
 
-	rev = readl_relaxed(anatop_base + ANADIG_DIGPROG_IMX8MM);
+	*socrev = readl_relaxed(anatop_base + ANADIG_DIGPROG_IMX8MM);
 
 	iounmap(anatop_base);
 	of_node_put(np);
 
-	imx8mm_soc_uid();
+	return imx8mm_soc_uid();
 
-	return rev;
+err_iomap:
+	of_node_put(np);
+	return ret;
 }
 
 static const struct imx8_soc_data imx8mq_soc_data = {
@@ -184,7 +212,7 @@ static __maybe_unused const struct of_device_id imx8_soc_match[] = {
 	kasprintf(GFP_KERNEL, "%d.%d", (soc_rev >> 4) & 0xf,  soc_rev & 0xf) : \
 	"unknown"
 
-static int __init imx8_soc_init(void)
+static int imx8m_soc_probe(struct platform_device *pdev)
 {
 	struct soc_device_attribute *soc_dev_attr;
 	struct soc_device *soc_dev;
@@ -212,8 +240,11 @@ static int __init imx8_soc_init(void)
 	data = id->data;
 	if (data) {
 		soc_dev_attr->soc_id = data->name;
-		if (data->soc_revision)
-			soc_rev = data->soc_revision();
+		if (data->soc_revision) {
+			ret = data->soc_revision(&soc_rev);
+			if (ret)
+				goto free_soc;
+		}
 	}
 
 	soc_dev_attr->revision = imx8_revision(soc_rev);
@@ -251,6 +282,38 @@ static int __init imx8_soc_init(void)
 	kfree(soc_dev_attr);
 	return ret;
 }
+
+static struct platform_driver imx8m_soc_driver = {
+	.probe = imx8m_soc_probe,
+	.driver = {
+		.name = "imx8m-soc",
+	},
+};
+
+static int __init imx8_soc_init(void)
+{
+	struct platform_device *pdev;
+	int ret;
+
+	/* No match means this is non-i.MX8M hardware, do nothing. */
+	if (!of_match_node(imx8_soc_match, of_root))
+		return 0;
+
+	ret = platform_driver_register(&imx8m_soc_driver);
+	if (ret) {
+		pr_err("Failed to register imx8m-soc platform driver: %d\n", ret);
+		return ret;
+	}
+
+	pdev = platform_device_register_simple("imx8m-soc", -1, NULL, 0);
+	if (IS_ERR(pdev)) {
+		pr_err("Failed to register imx8m-soc platform device: %ld\n", PTR_ERR(pdev));
+		platform_driver_unregister(&imx8m_soc_driver);
+		return PTR_ERR(pdev);
+	}
+
+	return 0;
+}
 device_initcall(imx8_soc_init);
 MODULE_DESCRIPTION("NXP i.MX8M SoC driver");
 MODULE_LICENSE("GPL");
-- 
2.45.2

[PATCH v4 2/3] soc: imx8m: Remove global soc_uid

[Marek Vasut]

The static global soc_uid is only ever used as kasprintf() parameter in
imx8m_soc_probe(). Pass pointer to local u64 variable to .soc_revision()
callback instead and let the .soc_revision() callback fill in the content.
Remove the unnecessary static global variable.

Signed-off-by: Marek Vasut <marex@denx.de>
---
Cc: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Fabio Estevam <festevam@gmail.com>
Cc: Jeff Johnson <quic_jjohnson@quicinc.com>
Cc: Neil Armstrong <neil.armstrong@linaro.org>
Cc: Pengutronix Kernel Team <kernel@pengutronix.de>
Cc: Saravana Kannan <saravanak@google.com>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: imx@lists.linux.dev
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
---
V3: New patch
V4: No change
---
 drivers/soc/imx/soc-imx8m.c | 31 +++++++++++++++----------------
 1 file changed, 15 insertions(+), 16 deletions(-)

diff --git a/drivers/soc/imx/soc-imx8m.c b/drivers/soc/imx/soc-imx8m.c
index 5ea8887828c06..966593320e28d 100644
--- a/drivers/soc/imx/soc-imx8m.c
+++ b/drivers/soc/imx/soc-imx8m.c
@@ -30,11 +30,9 @@
 
 struct imx8_soc_data {
 	char *name;
-	int (*soc_revision)(u32 *socrev);
+	int (*soc_revision)(u32 *socrev, u64 *socuid);
 };
 
-static u64 soc_uid;
-
 #ifdef CONFIG_HAVE_ARM_SMCCC
 static u32 imx8mq_soc_revision_from_atf(void)
 {
@@ -51,7 +49,7 @@ static u32 imx8mq_soc_revision_from_atf(void)
 static inline u32 imx8mq_soc_revision_from_atf(void) { return 0; };
 #endif
 
-static int imx8mq_soc_revision(u32 *socrev)
+static int imx8mq_soc_revision(u32 *socrev, u64 *socuid)
 {
 	struct device_node *np;
 	void __iomem *ocotp_base;
@@ -89,9 +87,9 @@ static int imx8mq_soc_revision(u32 *socrev)
 			rev = REV_B1;
 	}
 
-	soc_uid = readl_relaxed(ocotp_base + OCOTP_UID_HIGH);
-	soc_uid <<= 32;
-	soc_uid |= readl_relaxed(ocotp_base + OCOTP_UID_LOW);
+	*socuid = readl_relaxed(ocotp_base + OCOTP_UID_HIGH);
+	*socuid <<= 32;
+	*socuid |= readl_relaxed(ocotp_base + OCOTP_UID_LOW);
 
 	*socrev = rev;
 
@@ -109,7 +107,7 @@ static int imx8mq_soc_revision(u32 *socrev)
 	return ret;
 }
 
-static int imx8mm_soc_uid(void)
+static int imx8mm_soc_uid(u64 *socuid)
 {
 	void __iomem *ocotp_base;
 	struct device_node *np;
@@ -136,9 +134,9 @@ static int imx8mm_soc_uid(void)
 
 	clk_prepare_enable(clk);
 
-	soc_uid = readl_relaxed(ocotp_base + OCOTP_UID_HIGH + offset);
-	soc_uid <<= 32;
-	soc_uid |= readl_relaxed(ocotp_base + OCOTP_UID_LOW + offset);
+	*socuid = readl_relaxed(ocotp_base + OCOTP_UID_HIGH + offset);
+	*socuid <<= 32;
+	*socuid |= readl_relaxed(ocotp_base + OCOTP_UID_LOW + offset);
 
 	clk_disable_unprepare(clk);
 	clk_put(clk);
@@ -151,7 +149,7 @@ static int imx8mm_soc_uid(void)
 	return ret;
 }
 
-static int imx8mm_soc_revision(u32 *socrev)
+static int imx8mm_soc_revision(u32 *socrev, u64 *socuid)
 {
 	struct device_node *np;
 	void __iomem *anatop_base;
@@ -172,7 +170,7 @@ static int imx8mm_soc_revision(u32 *socrev)
 	iounmap(anatop_base);
 	of_node_put(np);
 
-	return imx8mm_soc_uid();
+	return imx8mm_soc_uid(socuid);
 
 err_iomap:
 	of_node_put(np);
@@ -215,10 +213,11 @@ static __maybe_unused const struct of_device_id imx8_soc_match[] = {
 static int imx8m_soc_probe(struct platform_device *pdev)
 {
 	struct soc_device_attribute *soc_dev_attr;
-	struct soc_device *soc_dev;
+	const struct imx8_soc_data *data;
 	const struct of_device_id *id;
+	struct soc_device *soc_dev;
 	u32 soc_rev = 0;
-	const struct imx8_soc_data *data;
+	u64 soc_uid = 0;
 	int ret;
 
 	soc_dev_attr = kzalloc(sizeof(*soc_dev_attr), GFP_KERNEL);
@@ -241,7 +240,7 @@ static int imx8m_soc_probe(struct platform_device *pdev)
 	if (data) {
 		soc_dev_attr->soc_id = data->name;
 		if (data->soc_revision) {
-			ret = data->soc_revision(&soc_rev);
+			ret = data->soc_revision(&soc_rev, &soc_uid);
 			if (ret)
 				goto free_soc;
 		}
-- 
2.45.2

[PATCH v4 3/3] soc: imx8m: Use devm_* to simplify probe failure handling

[Marek Vasut]

Use device managed functions to simplify handling of failures during
probe. Remove fail paths which are no longer necessary.

Signed-off-by: Marek Vasut <marex@denx.de>
---
Cc: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Fabio Estevam <festevam@gmail.com>
Cc: Jeff Johnson <quic_jjohnson@quicinc.com>
Cc: Neil Armstrong <neil.armstrong@linaro.org>
Cc: Pengutronix Kernel Team <kernel@pengutronix.de>
Cc: Saravana Kannan <saravanak@google.com>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: imx@lists.linux.dev
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
---
V4: New patch
---
 drivers/soc/imx/soc-imx8m.c | 92 ++++++++++++-------------------------
 1 file changed, 29 insertions(+), 63 deletions(-)

diff --git a/drivers/soc/imx/soc-imx8m.c b/drivers/soc/imx/soc-imx8m.c
index 966593320e28d..8ac7658e3d525 100644
--- a/drivers/soc/imx/soc-imx8m.c
+++ b/drivers/soc/imx/soc-imx8m.c
@@ -51,22 +51,20 @@ static inline u32 imx8mq_soc_revision_from_atf(void) { return 0; };
 
 static int imx8mq_soc_revision(u32 *socrev, u64 *socuid)
 {
-	struct device_node *np;
+	struct device_node *np __free(device_node) =
+		of_find_compatible_node(NULL, NULL, "fsl,imx8mq-ocotp");
 	void __iomem *ocotp_base;
 	u32 magic;
 	u32 rev;
 	struct clk *clk;
 	int ret;
 
-	np = of_find_compatible_node(NULL, NULL, "fsl,imx8mq-ocotp");
 	if (!np)
 		return -EINVAL;
 
 	ocotp_base = of_iomap(np, 0);
-	if (!ocotp_base) {
-		ret = -EINVAL;
-		goto err_iomap;
-	}
+	if (!ocotp_base)
+		return -EINVAL;
 
 	clk = of_clk_get_by_name(np, NULL);
 	if (IS_ERR(clk)) {
@@ -96,35 +94,30 @@ static int imx8mq_soc_revision(u32 *socrev, u64 *socuid)
 	clk_disable_unprepare(clk);
 	clk_put(clk);
 	iounmap(ocotp_base);
-	of_node_put(np);
 
 	return 0;
 
 err_clk:
 	iounmap(ocotp_base);
-err_iomap:
-	of_node_put(np);
 	return ret;
 }
 
 static int imx8mm_soc_uid(u64 *socuid)
 {
+	struct device_node *np __free(device_node) =
+		of_find_compatible_node(NULL, NULL, "fsl,imx8mm-ocotp");
 	void __iomem *ocotp_base;
-	struct device_node *np;
 	struct clk *clk;
 	int ret = 0;
 	u32 offset = of_machine_is_compatible("fsl,imx8mp") ?
 		     IMX8MP_OCOTP_UID_OFFSET : 0;
 
-	np = of_find_compatible_node(NULL, NULL, "fsl,imx8mm-ocotp");
 	if (!np)
 		return -EINVAL;
 
 	ocotp_base = of_iomap(np, 0);
-	if (!ocotp_base) {
-		ret = -EINVAL;
-		goto err_iomap;
-	}
+	if (!ocotp_base)
+		return -EINVAL;
 
 	clk = of_clk_get_by_name(np, NULL);
 	if (IS_ERR(clk)) {
@@ -143,38 +136,27 @@ static int imx8mm_soc_uid(u64 *socuid)
 
 err_clk:
 	iounmap(ocotp_base);
-err_iomap:
-	of_node_put(np);
-
 	return ret;
 }
 
 static int imx8mm_soc_revision(u32 *socrev, u64 *socuid)
 {
-	struct device_node *np;
+	struct device_node *np __free(device_node) =
+		of_find_compatible_node(NULL, NULL, "fsl,imx8mm-anatop");
 	void __iomem *anatop_base;
-	int ret;
 
-	np = of_find_compatible_node(NULL, NULL, "fsl,imx8mm-anatop");
 	if (!np)
 		return -EINVAL;
 
 	anatop_base = of_iomap(np, 0);
-	if (!anatop_base) {
-		ret = -EINVAL;
-		goto err_iomap;
-	}
+	if (!anatop_base)
+		return -EINVAL;
 
 	*socrev = readl_relaxed(anatop_base + ANADIG_DIGPROG_IMX8MM);
 
 	iounmap(anatop_base);
-	of_node_put(np);
 
 	return imx8mm_soc_uid(socuid);
-
-err_iomap:
-	of_node_put(np);
-	return ret;
 }
 
 static const struct imx8_soc_data imx8mq_soc_data = {
@@ -205,22 +187,23 @@ static __maybe_unused const struct of_device_id imx8_soc_match[] = {
 	{ }
 };
 
-#define imx8_revision(soc_rev) \
-	soc_rev ? \
-	kasprintf(GFP_KERNEL, "%d.%d", (soc_rev >> 4) & 0xf,  soc_rev & 0xf) : \
+#define imx8_revision(dev, soc_rev) \
+	(soc_rev) ? \
+	devm_kasprintf((dev), GFP_KERNEL, "%d.%d", ((soc_rev) >> 4) & 0xf, (soc_rev) & 0xf) : \
 	"unknown"
 
 static int imx8m_soc_probe(struct platform_device *pdev)
 {
 	struct soc_device_attribute *soc_dev_attr;
 	const struct imx8_soc_data *data;
+	struct device *dev = &pdev->dev;
 	const struct of_device_id *id;
 	struct soc_device *soc_dev;
 	u32 soc_rev = 0;
 	u64 soc_uid = 0;
 	int ret;
 
-	soc_dev_attr = kzalloc(sizeof(*soc_dev_attr), GFP_KERNEL);
+	soc_dev_attr = devm_kzalloc(dev, sizeof(*soc_dev_attr), GFP_KERNEL);
 	if (!soc_dev_attr)
 		return -ENOMEM;
 
@@ -228,13 +211,11 @@ static int imx8m_soc_probe(struct platform_device *pdev)
 
 	ret = of_property_read_string(of_root, "model", &soc_dev_attr->machine);
 	if (ret)
-		goto free_soc;
+		return ret;
 
 	id = of_match_node(imx8_soc_match, of_root);
-	if (!id) {
-		ret = -ENODEV;
-		goto free_soc;
-	}
+	if (!id)
+		return -ENODEV;
 
 	data = id->data;
 	if (data) {
@@ -242,27 +223,21 @@ static int imx8m_soc_probe(struct platform_device *pdev)
 		if (data->soc_revision) {
 			ret = data->soc_revision(&soc_rev, &soc_uid);
 			if (ret)
-				goto free_soc;
+				return ret;
 		}
 	}
 
-	soc_dev_attr->revision = imx8_revision(soc_rev);
-	if (!soc_dev_attr->revision) {
-		ret = -ENOMEM;
-		goto free_soc;
-	}
+	soc_dev_attr->revision = imx8_revision(dev, soc_rev);
+	if (!soc_dev_attr->revision)
+		return -ENOMEM;
 
-	soc_dev_attr->serial_number = kasprintf(GFP_KERNEL, "%016llX", soc_uid);
-	if (!soc_dev_attr->serial_number) {
-		ret = -ENOMEM;
-		goto free_rev;
-	}
+	soc_dev_attr->serial_number = devm_kasprintf(dev, GFP_KERNEL, "%016llX", soc_uid);
+	if (!soc_dev_attr->serial_number)
+		return -ENOMEM;
 
 	soc_dev = soc_device_register(soc_dev_attr);
-	if (IS_ERR(soc_dev)) {
-		ret = PTR_ERR(soc_dev);
-		goto free_serial_number;
-	}
+	if (IS_ERR(soc_dev))
+		return PTR_ERR(soc_dev);
 
 	pr_info("SoC: %s revision %s\n", soc_dev_attr->soc_id,
 		soc_dev_attr->revision);
@@ -271,15 +246,6 @@ static int imx8m_soc_probe(struct platform_device *pdev)
 		platform_device_register_simple("imx-cpufreq-dt", -1, NULL, 0);
 
 	return 0;
-
-free_serial_number:
-	kfree(soc_dev_attr->serial_number);
-free_rev:
-	if (strcmp(soc_dev_attr->revision, "unknown"))
-		kfree(soc_dev_attr->revision);
-free_soc:
-	kfree(soc_dev_attr);
-	return ret;
 }
 
 static struct platform_driver imx8m_soc_driver = {
-- 
2.45.2

Re: [PATCH v4 1/3] soc: imx8m: Probe the SoC driver as platform driver

[Shawn Guo]

On Sun, Sep 29, 2024 at 08:49:16PM +0200, Marek Vasut wrote:
> With driver_async_probe=* on kernel command line, the following trace is
> produced because on i.MX8M Plus hardware because the soc-imx8m.c driver
> calls of_clk_get_by_name() which returns -EPROBE_DEFER because the clock
> driver is not yet probed. This was not detected during regular testing
> without driver_async_probe.
> 
> Convert the SoC code to platform driver and instantiate a platform device
> in its current device_initcall() to probe the platform driver. Rework
> .soc_revision callback to always return valid error code and return SoC
> revision via parameter. This way, if anything in the .soc_revision callback
> return -EPROBE_DEFER, it gets propagated to .probe and the .probe will get
> retried later.
> 
> "
> ------------[ cut here ]------------
> WARNING: CPU: 1 PID: 1 at drivers/soc/imx/soc-imx8m.c:115 imx8mm_soc_revision+0xdc/0x180
> CPU: 1 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.11.0-next-20240924-00002-g2062bb554dea #603
> Hardware name: DH electronics i.MX8M Plus DHCOM Premium Developer Kit (3) (DT)
> pstate: 20000005 (nzCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
> pc : imx8mm_soc_revision+0xdc/0x180
> lr : imx8mm_soc_revision+0xd0/0x180
> sp : ffff8000821fbcc0
> x29: ffff8000821fbce0 x28: 0000000000000000 x27: ffff800081810120
> x26: ffff8000818a9970 x25: 0000000000000006 x24: 0000000000824311
> x23: ffff8000817f42c8 x22: ffff0000df8be210 x21: fffffffffffffdfb
> x20: ffff800082780000 x19: 0000000000000001 x18: ffffffffffffffff
> x17: ffff800081fff418 x16: ffff8000823e1000 x15: ffff0000c03b65e8
> x14: ffff0000c00051b0 x13: ffff800082790000 x12: 0000000000000801
> x11: ffff80008278ffff x10: ffff80008209d3a6 x9 : ffff80008062e95c
> x8 : ffff8000821fb9a0 x7 : 0000000000000000 x6 : 00000000000080e3
> x5 : ffff0000df8c03d8 x4 : 0000000000000000 x3 : 0000000000000000
> x2 : 0000000000000000 x1 : fffffffffffffdfb x0 : fffffffffffffdfb
> Call trace:
>  imx8mm_soc_revision+0xdc/0x180
>  imx8_soc_init+0xb0/0x1e0
>  do_one_initcall+0x94/0x1a8
>  kernel_init_freeable+0x240/0x2a8
>  kernel_init+0x28/0x140
>  ret_from_fork+0x10/0x20
> ---[ end trace 0000000000000000 ]---
> SoC: i.MX8MP revision 1.1
> "
> 
> Signed-off-by: Marek Vasut <marex@denx.de>

Applied all, thanks!