FAILED: patch "[PATCH] mfd: twl-core: Unregister the auxiliary platform device on unbind" failed to apply to 5.15-stable tree

FAILED: patch "[PATCH] mfd: twl-core: Unregister the auxiliary platform device on unbind" failed to apply to 5.15-stable tree

[Sasha Levin]

The patch below does not apply to the 5.15-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x 3c5c55d979ddcb0765ce531bc7ba173c87c8712a
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '20261107060010-failed-5.15-3c5c55d979dd@kernel.org' --subject-prefix 'PATCH 5.15.y' 'HEAD^..'

Thanks,
Sasha

------------------ original commit in Linus's tree ------------------

From 3c5c55d979ddcb0765ce531bc7ba173c87c8712a Mon Sep 17 00:00:00 2001
From: Myeonghun Pak <mhun512@gmail.com>
Date: Sun, 13 Sep 2026 16:50:12 -0400
Subject: [PATCH] mfd: twl-core: Unregister the auxiliary platform device on
 unbind

twl_probe() registers a standalone platform device named "twl", but keeps
its pointer only in a local variable. Probe errors unregister the device,
while successful probe leaves no way for twl_remove() to release it. The
platform device therefore remains registered after the I2C driver unbinds.

Register a managed action on the I2C device immediately after adding the
platform device. This unregisters it on probe failure and driver unbind,
and also handles failure to register the action itself. Remove the manual
error-path unregister to avoid releasing the device twice.

This issue was identified during our ongoing static-analysis research while
reviewing kernel code.

Fixes: defa6be1c821 ("mfd: Fix compile for twl-core.c by removing cpu_is_omap usage")
Cc: stable@vger.kernel.org
Assisted-by: OpenAI:GPT-5.6
Co-developed-by: Ijae Kim <ae878000@gmail.com>
Signed-off-by: Ijae Kim <ae878000@gmail.com>
Signed-off-by: Myeonghun Pak <mhun512@gmail.com>
Link: https://patch.msgid.link/20260913205013.54777-1-mhun512@gmail.com
Signed-off-by: Lee Jones <lee@kernel.org>
---
 drivers/mfd/twl-core.c | 23 +++++++++++++++--------
 1 file changed, 15 insertions(+), 8 deletions(-)

diff --git a/drivers/mfd/twl-core.c b/drivers/mfd/twl-core.c
index b7d749208131b..7fbce76efd305 100644
--- a/drivers/mfd/twl-core.c
+++ b/drivers/mfd/twl-core.c
@@ -719,6 +719,11 @@ static const struct mfd_cell twl6032_cells[] = {
 	{ .name = "twl6032-clk" },
 };
 
+static void twl_unregister_device(void *data)
+{
+	platform_device_unregister(data);
+}
+
 /* NOTE: This driver only handles a single twl4030/tps659x0 chip */
 static int
 twl_probe(struct i2c_client *client)
@@ -754,17 +759,22 @@ twl_probe(struct i2c_client *client)
 		return status;
 	}
 
+	status = devm_add_action_or_reset(&client->dev, twl_unregister_device,
+					  pdev);
+	if (status)
+		return status;
+
 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
 		dev_dbg(&client->dev, "can't talk I2C?\n");
 		status = -EIO;
-		goto free;
+		goto out;
 	}
 
 	twl_priv = devm_kzalloc(&client->dev, sizeof(struct twl_private),
 				GFP_KERNEL);
 	if (!twl_priv) {
 		status = -ENOMEM;
-		goto free;
+		goto out;
 	}
 
 	if ((id->driver_data) & TWL6030_CLASS) {
@@ -784,7 +794,7 @@ twl_probe(struct i2c_client *client)
 					 GFP_KERNEL);
 	if (!twl_priv->twl_modules) {
 		status = -ENOMEM;
-		goto free;
+		goto out;
 	}
 
 	for (i = 0; i < num_slaves; i++) {
@@ -880,7 +890,7 @@ twl_probe(struct i2c_client *client)
 		status = devm_mfd_add_devices(&client->dev, PLATFORM_DEVID_NONE,
 					      cells, num_cells, NULL, 0, NULL);
 		if (status < 0)
-			goto free;
+			goto out;
 
 		if (of_device_is_system_power_controller(node)) {
 			if (!pm_power_off)
@@ -896,10 +906,7 @@ twl_probe(struct i2c_client *client)
 fail:
 	if (status < 0)
 		twl_remove(client);
-free:
-	if (status < 0)
-		platform_device_unregister(pdev);
-
+out:
 	return status;
 }
 
-- 
2.53.0

[PATCH 5.15.y 1/3] mfd: twl: Remove platform data support

[Sasha Levin]

From: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

[ Upstream commit 4a346a03a63cb45f7766d9d6559cf3fee783e926 ]

There is no in-tree machine that provides a struct twl4030_platform_data
since commit e92fc4f04a34 ("ARM: OMAP2+: Drop legacy board file for
LDP"). So assume dev_get_platdata() returns NULL in twl_probe() and
simplify accordingly.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20220614152148.252820-1-u.kleine-koenig@pengutronix.de
Stable-dep-of: 3c5c55d979dd ("mfd: twl-core: Unregister the auxiliary platform device on unbind")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/mfd/twl-core.c  | 323 +---------------------------------------
 include/linux/mfd/twl.h |  55 -------
 2 files changed, 5 insertions(+), 373 deletions(-)

diff --git a/drivers/mfd/twl-core.c b/drivers/mfd/twl-core.c
index 289b556dede28..ae5f101167b45 100644
--- a/drivers/mfd/twl-core.c
+++ b/drivers/mfd/twl-core.c
@@ -656,309 +656,6 @@ static inline struct device *add_child(unsigned mod_no, const char *name,
 		can_wakeup, irq0, irq1);
 }
 
-static struct device *
-add_regulator_linked(int num, struct regulator_init_data *pdata,
-		struct regulator_consumer_supply *consumers,
-		unsigned num_consumers, unsigned long features)
-{
-	struct twl_regulator_driver_data drv_data;
-
-	/* regulator framework demands init_data ... */
-	if (!pdata)
-		return NULL;
-
-	if (consumers) {
-		pdata->consumer_supplies = consumers;
-		pdata->num_consumer_supplies = num_consumers;
-	}
-
-	if (pdata->driver_data) {
-		/* If we have existing drv_data, just add the flags */
-		struct twl_regulator_driver_data *tmp;
-		tmp = pdata->driver_data;
-		tmp->features |= features;
-	} else {
-		/* add new driver data struct, used only during init */
-		drv_data.features = features;
-		drv_data.set_voltage = NULL;
-		drv_data.get_voltage = NULL;
-		drv_data.data = NULL;
-		pdata->driver_data = &drv_data;
-	}
-
-	/* NOTE:  we currently ignore regulator IRQs, e.g. for short circuits */
-	return add_numbered_child(TWL_MODULE_PM_MASTER, "twl_reg", num,
-		pdata, sizeof(*pdata), false, 0, 0);
-}
-
-static struct device *
-add_regulator(int num, struct regulator_init_data *pdata,
-		unsigned long features)
-{
-	return add_regulator_linked(num, pdata, NULL, 0, features);
-}
-
-/*
- * NOTE:  We know the first 8 IRQs after pdata->base_irq are
- * for the PIH, and the next are for the PWR_INT SIH, since
- * that's how twl_init_irq() sets things up.
- */
-
-static int
-add_children(struct twl4030_platform_data *pdata, unsigned irq_base,
-		unsigned long features)
-{
-	struct device	*child;
-
-	if (IS_ENABLED(CONFIG_GPIO_TWL4030) && pdata->gpio) {
-		child = add_child(TWL4030_MODULE_GPIO, "twl4030_gpio",
-				pdata->gpio, sizeof(*pdata->gpio),
-				false, irq_base + GPIO_INTR_OFFSET, 0);
-		if (IS_ERR(child))
-			return PTR_ERR(child);
-	}
-
-	if (IS_ENABLED(CONFIG_KEYBOARD_TWL4030) && pdata->keypad) {
-		child = add_child(TWL4030_MODULE_KEYPAD, "twl4030_keypad",
-				pdata->keypad, sizeof(*pdata->keypad),
-				true, irq_base + KEYPAD_INTR_OFFSET, 0);
-		if (IS_ERR(child))
-			return PTR_ERR(child);
-	}
-
-	if (IS_ENABLED(CONFIG_TWL4030_MADC) && pdata->madc &&
-	    twl_class_is_4030()) {
-		child = add_child(TWL4030_MODULE_MADC, "twl4030_madc",
-				pdata->madc, sizeof(*pdata->madc),
-				true, irq_base + MADC_INTR_OFFSET, 0);
-		if (IS_ERR(child))
-			return PTR_ERR(child);
-	}
-
-	if (IS_ENABLED(CONFIG_RTC_DRV_TWL4030)) {
-		/*
-		 * REVISIT platform_data here currently might expose the
-		 * "msecure" line ... but for now we just expect board
-		 * setup to tell the chip "it's always ok to SET_TIME".
-		 * Eventually, Linux might become more aware of such
-		 * HW security concerns, and "least privilege".
-		 */
-		child = add_child(TWL_MODULE_RTC, "twl_rtc", NULL, 0,
-				true, irq_base + RTC_INTR_OFFSET, 0);
-		if (IS_ERR(child))
-			return PTR_ERR(child);
-	}
-
-	if (IS_ENABLED(CONFIG_PWM_TWL)) {
-		child = add_child(TWL_MODULE_PWM, "twl-pwm", NULL, 0,
-				  false, 0, 0);
-		if (IS_ERR(child))
-			return PTR_ERR(child);
-	}
-
-	if (IS_ENABLED(CONFIG_PWM_TWL_LED)) {
-		child = add_child(TWL_MODULE_LED, "twl-pwmled", NULL, 0,
-				  false, 0, 0);
-		if (IS_ERR(child))
-			return PTR_ERR(child);
-	}
-
-	if (IS_ENABLED(CONFIG_TWL4030_USB) && pdata->usb &&
-	    twl_class_is_4030()) {
-
-		static struct regulator_consumer_supply usb1v5 = {
-			.supply =	"usb1v5",
-		};
-		static struct regulator_consumer_supply usb1v8 = {
-			.supply =	"usb1v8",
-		};
-		static struct regulator_consumer_supply usb3v1 = {
-			.supply =	"usb3v1",
-		};
-
-	/* First add the regulators so that they can be used by transceiver */
-		if (IS_ENABLED(CONFIG_REGULATOR_TWL4030)) {
-			/* this is a template that gets copied */
-			struct regulator_init_data usb_fixed = {
-				.constraints.valid_modes_mask =
-					REGULATOR_MODE_NORMAL
-					| REGULATOR_MODE_STANDBY,
-				.constraints.valid_ops_mask =
-					REGULATOR_CHANGE_MODE
-					| REGULATOR_CHANGE_STATUS,
-			};
-
-			child = add_regulator_linked(TWL4030_REG_VUSB1V5,
-						      &usb_fixed, &usb1v5, 1,
-						      features);
-			if (IS_ERR(child))
-				return PTR_ERR(child);
-
-			child = add_regulator_linked(TWL4030_REG_VUSB1V8,
-						      &usb_fixed, &usb1v8, 1,
-						      features);
-			if (IS_ERR(child))
-				return PTR_ERR(child);
-
-			child = add_regulator_linked(TWL4030_REG_VUSB3V1,
-						      &usb_fixed, &usb3v1, 1,
-						      features);
-			if (IS_ERR(child))
-				return PTR_ERR(child);
-
-		}
-
-		child = add_child(TWL_MODULE_USB, "twl4030_usb",
-				pdata->usb, sizeof(*pdata->usb), true,
-				/* irq0 = USB_PRES, irq1 = USB */
-				irq_base + USB_PRES_INTR_OFFSET,
-				irq_base + USB_INTR_OFFSET);
-
-		if (IS_ERR(child))
-			return PTR_ERR(child);
-
-		/* we need to connect regulators to this transceiver */
-		if (IS_ENABLED(CONFIG_REGULATOR_TWL4030) && child) {
-			usb1v5.dev_name = dev_name(child);
-			usb1v8.dev_name = dev_name(child);
-			usb3v1.dev_name = dev_name(child);
-		}
-	}
-
-	if (IS_ENABLED(CONFIG_TWL4030_WATCHDOG) && twl_class_is_4030()) {
-		child = add_child(TWL_MODULE_PM_RECEIVER, "twl4030_wdt", NULL,
-				  0, false, 0, 0);
-		if (IS_ERR(child))
-			return PTR_ERR(child);
-	}
-
-	if (IS_ENABLED(CONFIG_INPUT_TWL4030_PWRBUTTON) && twl_class_is_4030()) {
-		child = add_child(TWL_MODULE_PM_MASTER, "twl4030_pwrbutton",
-				  NULL, 0, true, irq_base + 8 + 0, 0);
-		if (IS_ERR(child))
-			return PTR_ERR(child);
-	}
-
-	if (IS_ENABLED(CONFIG_MFD_TWL4030_AUDIO) && pdata->audio &&
-	    twl_class_is_4030()) {
-		child = add_child(TWL4030_MODULE_AUDIO_VOICE, "twl4030-audio",
-				pdata->audio, sizeof(*pdata->audio),
-				false, 0, 0);
-		if (IS_ERR(child))
-			return PTR_ERR(child);
-	}
-
-	/* twl4030 regulators */
-	if (IS_ENABLED(CONFIG_REGULATOR_TWL4030) && twl_class_is_4030()) {
-		child = add_regulator(TWL4030_REG_VPLL1, pdata->vpll1,
-					features);
-		if (IS_ERR(child))
-			return PTR_ERR(child);
-
-		child = add_regulator(TWL4030_REG_VIO, pdata->vio,
-					features);
-		if (IS_ERR(child))
-			return PTR_ERR(child);
-
-		child = add_regulator(TWL4030_REG_VDD1, pdata->vdd1,
-					features);
-		if (IS_ERR(child))
-			return PTR_ERR(child);
-
-		child = add_regulator(TWL4030_REG_VDD2, pdata->vdd2,
-					features);
-		if (IS_ERR(child))
-			return PTR_ERR(child);
-
-		child = add_regulator(TWL4030_REG_VMMC1, pdata->vmmc1,
-					features);
-		if (IS_ERR(child))
-			return PTR_ERR(child);
-
-		child = add_regulator(TWL4030_REG_VDAC, pdata->vdac,
-					features);
-		if (IS_ERR(child))
-			return PTR_ERR(child);
-
-		child = add_regulator((features & TWL4030_VAUX2)
-					? TWL4030_REG_VAUX2_4030
-					: TWL4030_REG_VAUX2,
-				pdata->vaux2, features);
-		if (IS_ERR(child))
-			return PTR_ERR(child);
-
-		child = add_regulator(TWL4030_REG_VINTANA1, pdata->vintana1,
-					features);
-		if (IS_ERR(child))
-			return PTR_ERR(child);
-
-		child = add_regulator(TWL4030_REG_VINTANA2, pdata->vintana2,
-					features);
-		if (IS_ERR(child))
-			return PTR_ERR(child);
-
-		child = add_regulator(TWL4030_REG_VINTDIG, pdata->vintdig,
-					features);
-		if (IS_ERR(child))
-			return PTR_ERR(child);
-	}
-
-	/* maybe add LDOs that are omitted on cost-reduced parts */
-	if (IS_ENABLED(CONFIG_REGULATOR_TWL4030) && !(features & TPS_SUBSET)
-	  && twl_class_is_4030()) {
-		child = add_regulator(TWL4030_REG_VPLL2, pdata->vpll2,
-					features);
-		if (IS_ERR(child))
-			return PTR_ERR(child);
-
-		child = add_regulator(TWL4030_REG_VMMC2, pdata->vmmc2,
-					features);
-		if (IS_ERR(child))
-			return PTR_ERR(child);
-
-		child = add_regulator(TWL4030_REG_VSIM, pdata->vsim,
-					features);
-		if (IS_ERR(child))
-			return PTR_ERR(child);
-
-		child = add_regulator(TWL4030_REG_VAUX1, pdata->vaux1,
-					features);
-		if (IS_ERR(child))
-			return PTR_ERR(child);
-
-		child = add_regulator(TWL4030_REG_VAUX3, pdata->vaux3,
-					features);
-		if (IS_ERR(child))
-			return PTR_ERR(child);
-
-		child = add_regulator(TWL4030_REG_VAUX4, pdata->vaux4,
-					features);
-		if (IS_ERR(child))
-			return PTR_ERR(child);
-	}
-
-	if (IS_ENABLED(CONFIG_CHARGER_TWL4030) && pdata->bci &&
-			!(features & (TPS_SUBSET | TWL5031))) {
-		child = add_child(TWL_MODULE_MAIN_CHARGE, "twl4030_bci",
-				pdata->bci, sizeof(*pdata->bci), false,
-				/* irq0 = CHG_PRES, irq1 = BCI */
-				irq_base + BCI_PRES_INTR_OFFSET,
-				irq_base + BCI_INTR_OFFSET);
-		if (IS_ERR(child))
-			return PTR_ERR(child);
-	}
-
-	if (IS_ENABLED(CONFIG_TWL4030_POWER) && pdata->power) {
-		child = add_child(TWL_MODULE_PM_MASTER, "twl4030_power",
-				  pdata->power, sizeof(*pdata->power), false,
-				  0, 0);
-		if (IS_ERR(child))
-			return PTR_ERR(child);
-	}
-
-	return 0;
-}
-
 /*----------------------------------------------------------------------*/
 
 /*
@@ -987,8 +684,7 @@ static inline int unprotect_pm_master(void)
 	return e;
 }
 
-static void clocks_init(struct device *dev,
-			struct twl4030_clock_init_data *clock)
+static void clocks_init(struct device *dev)
 {
 	int e = 0;
 	struct clk *osc;
@@ -1018,8 +714,6 @@ static void clocks_init(struct device *dev,
 	}
 
 	ctrl |= HIGH_PERF_SQ;
-	if (clock && clock->ck32k_lowpwr_enable)
-		ctrl |= CK32K_LOWPWR_EN;
 
 	e |= unprotect_pm_master();
 	/* effect->MADC+USB ck en */
@@ -1067,7 +761,6 @@ static struct of_dev_auxdata twl_auxdata_lookup[] = {
 static int
 twl_probe(struct i2c_client *client, const struct i2c_device_id *id)
 {
-	struct twl4030_platform_data	*pdata = dev_get_platdata(&client->dev);
 	struct device_node		*node = client->dev.of_node;
 	struct platform_device		*pdev;
 	const struct regmap_config	*twl_regmap_config;
@@ -1075,7 +768,7 @@ twl_probe(struct i2c_client *client, const struct i2c_device_id *id)
 	int				status;
 	unsigned			i, num_slaves;
 
-	if (!node && !pdata) {
+	if (!node) {
 		dev_err(&client->dev, "no platform data\n");
 		return -EINVAL;
 	}
@@ -1165,7 +858,7 @@ twl_probe(struct i2c_client *client, const struct i2c_device_id *id)
 	twl_priv->ready = true;
 
 	/* setup clock framework */
-	clocks_init(&client->dev, pdata ? pdata->clock : NULL);
+	clocks_init(&client->dev);
 
 	/* read TWL IDCODE Register */
 	if (twl_class_is_4030()) {
@@ -1213,14 +906,8 @@ twl_probe(struct i2c_client *client, const struct i2c_device_id *id)
 				 TWL4030_DCDC_GLOBAL_CFG);
 	}
 
-	if (node) {
-		if (pdata)
-			twl_auxdata_lookup[0].platform_data = pdata->gpio;
-		status = of_platform_populate(node, NULL, twl_auxdata_lookup,
-					      &client->dev);
-	} else {
-		status = add_children(pdata, irq_base, id->driver_data);
-	}
+	status = of_platform_populate(node, NULL, twl_auxdata_lookup,
+				      &client->dev);
 
 fail:
 	if (status < 0)
diff --git a/include/linux/mfd/twl.h b/include/linux/mfd/twl.h
index 8871cc5188a09..e426938eafd56 100644
--- a/include/linux/mfd/twl.h
+++ b/include/linux/mfd/twl.h
@@ -694,61 +694,6 @@ struct twl4030_audio_data {
 	unsigned int irq_base;
 };
 
-struct twl4030_platform_data {
-	struct twl4030_clock_init_data		*clock;
-	struct twl4030_bci_platform_data	*bci;
-	struct twl4030_gpio_platform_data	*gpio;
-	struct twl4030_madc_platform_data	*madc;
-	struct twl4030_keypad_data		*keypad;
-	struct twl4030_usb_data			*usb;
-	struct twl4030_power_data		*power;
-	struct twl4030_audio_data		*audio;
-
-	/* Common LDO regulators for TWL4030/TWL6030 */
-	struct regulator_init_data		*vdac;
-	struct regulator_init_data		*vaux1;
-	struct regulator_init_data		*vaux2;
-	struct regulator_init_data		*vaux3;
-	struct regulator_init_data		*vdd1;
-	struct regulator_init_data		*vdd2;
-	struct regulator_init_data		*vdd3;
-	/* TWL4030 LDO regulators */
-	struct regulator_init_data		*vpll1;
-	struct regulator_init_data		*vpll2;
-	struct regulator_init_data		*vmmc1;
-	struct regulator_init_data		*vmmc2;
-	struct regulator_init_data		*vsim;
-	struct regulator_init_data		*vaux4;
-	struct regulator_init_data		*vio;
-	struct regulator_init_data		*vintana1;
-	struct regulator_init_data		*vintana2;
-	struct regulator_init_data		*vintdig;
-	/* TWL6030 LDO regulators */
-	struct regulator_init_data              *vmmc;
-	struct regulator_init_data              *vpp;
-	struct regulator_init_data              *vusim;
-	struct regulator_init_data              *vana;
-	struct regulator_init_data              *vcxio;
-	struct regulator_init_data              *vusb;
-	struct regulator_init_data		*clk32kg;
-	struct regulator_init_data              *v1v8;
-	struct regulator_init_data              *v2v1;
-	/* TWL6032 LDO regulators */
-	struct regulator_init_data		*ldo1;
-	struct regulator_init_data		*ldo2;
-	struct regulator_init_data		*ldo3;
-	struct regulator_init_data		*ldo4;
-	struct regulator_init_data		*ldo5;
-	struct regulator_init_data		*ldo6;
-	struct regulator_init_data		*ldo7;
-	struct regulator_init_data		*ldoln;
-	struct regulator_init_data		*ldousb;
-	/* TWL6032 DCDC regulators */
-	struct regulator_init_data		*smps3;
-	struct regulator_init_data		*smps4;
-	struct regulator_init_data		*vio6025;
-};
-
 struct twl_regulator_driver_data {
 	int		(*set_voltage)(void *data, int target_uV);
 	int		(*get_voltage)(void *data);
-- 
2.53.0

[PATCH 5.15.y 2/3] mfd: twl-core: Use i2c_check_functionality as boolean value

[Sasha Levin]

From: Thorsten Blum <thorsten.blum@linux.dev>

[ Upstream commit 7ee4fa2674e51a0d100b9240cd8a50355141362f ]

i2c_check_functionality() returns a boolean status rather than an error
code - directly use it as a boolean value.

Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Link: https://patch.msgid.link/20260505114543.159381-2-thorsten.blum@linux.dev
Signed-off-by: Lee Jones <lee@kernel.org>
Stable-dep-of: 3c5c55d979dd ("mfd: twl-core: Unregister the auxiliary platform device on unbind")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/mfd/twl-core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/mfd/twl-core.c b/drivers/mfd/twl-core.c
index ae5f101167b45..acfc0b96b4a1a 100644
--- a/drivers/mfd/twl-core.c
+++ b/drivers/mfd/twl-core.c
@@ -791,7 +791,7 @@ twl_probe(struct i2c_client *client, const struct i2c_device_id *id)
 		return status;
 	}
 
-	if (i2c_check_functionality(client->adapter, I2C_FUNC_I2C) == 0) {
+	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
 		dev_dbg(&client->dev, "can't talk I2C?\n");
 		status = -EIO;
 		goto free;
-- 
2.53.0

[PATCH 5.15.y 3/3] mfd: twl-core: Unregister the auxiliary platform device on unbind

[Sasha Levin]

From: Myeonghun Pak <mhun512@gmail.com>

[ Upstream commit 3c5c55d979ddcb0765ce531bc7ba173c87c8712a ]

twl_probe() registers a standalone platform device named "twl", but keeps
its pointer only in a local variable. Probe errors unregister the device,
while successful probe leaves no way for twl_remove() to release it. The
platform device therefore remains registered after the I2C driver unbinds.

Register a managed action on the I2C device immediately after adding the
platform device. This unregisters it on probe failure and driver unbind,
and also handles failure to register the action itself. Remove the manual
error-path unregister to avoid releasing the device twice.

This issue was identified during our ongoing static-analysis research while
reviewing kernel code.

Fixes: defa6be1c821 ("mfd: Fix compile for twl-core.c by removing cpu_is_omap usage")
Cc: stable@vger.kernel.org
Assisted-by: OpenAI:GPT-5.6
Co-developed-by: Ijae Kim <ae878000@gmail.com>
Signed-off-by: Ijae Kim <ae878000@gmail.com>
Signed-off-by: Myeonghun Pak <mhun512@gmail.com>
Link: https://patch.msgid.link/20260913205013.54777-1-mhun512@gmail.com
Signed-off-by: Lee Jones <lee@kernel.org>
[ sashal: omitted the goto adjustment for the absent devm_mfd_add_devices() error path ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/mfd/twl-core.c | 21 ++++++++++++++-------
 1 file changed, 14 insertions(+), 7 deletions(-)

diff --git a/drivers/mfd/twl-core.c b/drivers/mfd/twl-core.c
index acfc0b96b4a1a..9b1ff86632122 100644
--- a/drivers/mfd/twl-core.c
+++ b/drivers/mfd/twl-core.c
@@ -757,6 +757,11 @@ static struct of_dev_auxdata twl_auxdata_lookup[] = {
 	{ /* sentinel */ },
 };
 
+static void twl_unregister_device(void *data)
+{
+	platform_device_unregister(data);
+}
+
 /* NOTE: This driver only handles a single twl4030/tps659x0 chip */
 static int
 twl_probe(struct i2c_client *client, const struct i2c_device_id *id)
@@ -791,17 +796,22 @@ twl_probe(struct i2c_client *client, const struct i2c_device_id *id)
 		return status;
 	}
 
+	status = devm_add_action_or_reset(&client->dev, twl_unregister_device,
+					  pdev);
+	if (status)
+		return status;
+
 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
 		dev_dbg(&client->dev, "can't talk I2C?\n");
 		status = -EIO;
-		goto free;
+		goto out;
 	}
 
 	twl_priv = devm_kzalloc(&client->dev, sizeof(struct twl_private),
 				GFP_KERNEL);
 	if (!twl_priv) {
 		status = -ENOMEM;
-		goto free;
+		goto out;
 	}
 
 	if ((id->driver_data) & TWL6030_CLASS) {
@@ -825,7 +835,7 @@ twl_probe(struct i2c_client *client, const struct i2c_device_id *id)
 					 GFP_KERNEL);
 	if (!twl_priv->twl_modules) {
 		status = -ENOMEM;
-		goto free;
+		goto out;
 	}
 
 	for (i = 0; i < num_slaves; i++) {
@@ -912,10 +922,7 @@ twl_probe(struct i2c_client *client, const struct i2c_device_id *id)
 fail:
 	if (status < 0)
 		twl_remove(client);
-free:
-	if (status < 0)
-		platform_device_unregister(pdev);
-
+out:
 	return status;
 }
 
-- 
2.53.0