FAILED: patch "[PATCH] i2c: core: fix adapter probe deferral loop" failed to apply to 6.1-stable tree

FAILED: patch "[PATCH] i2c: core: fix adapter probe deferral loop" failed to apply to 6.1-stable tree

[gregkh]

The patch below does not apply to the 6.1-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-6.1.y
git checkout FETCH_HEAD
git cherry-pick -x 158efa411c57111d87bf265a3776614f32d70007
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026071656-trivial-state-54ad@gregkh' --subject-prefix 'PATCH 6.1.y' 'HEAD^..'

Possible dependencies:



thanks,

greg k-h

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

From 158efa411c57111d87bf265a3776614f32d70007 Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan@kernel.org>
Date: Mon, 11 May 2026 16:37:09 +0200
Subject: [PATCH] i2c: core: fix adapter probe deferral loop

Drivers must not probe defer after having registered devices as that
will trigger a probe loop if the devices bind to a driver (cf. commit
fbc35b45f9f6 ("Add documentation on meaning of -EPROBE_DEFER")).

Move the recovery initialisation, where the GPIO lookup may fail, before
registering the adapter to prevent this.

Fixes: 75820314de26 ("i2c: core: add generic I2C GPIO recovery")
Cc: stable@vger.kernel.org	# 5.9
Cc: Codrin Ciubotariu <codrin.ciubotariu@microchip.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>

diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
index fa9db415e219..1caaa3b3ee10 100644
--- a/drivers/i2c/i2c-core-base.c
+++ b/drivers/i2c/i2c-core-base.c
@@ -1562,6 +1562,10 @@ static int i2c_register_adapter(struct i2c_adapter *adap)
 	adap->dev.type = &i2c_adapter_type;
 	device_initialize(&adap->dev);
 
+	res = i2c_init_recovery(adap);
+	if (res == -EPROBE_DEFER)
+		goto err_put_adap;
+
 	/*
 	 * This adapter can be used as a parent immediately after device_add(),
 	 * setup runtime-pm (especially ignore-children) before hand.
@@ -1583,10 +1587,6 @@ static int i2c_register_adapter(struct i2c_adapter *adap)
 	if (res)
 		goto out_reg;
 
-	res = i2c_init_recovery(adap);
-	if (res == -EPROBE_DEFER)
-		goto out_reg;
-
 	dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name);
 
 	/* create pre-declared device nodes */

[PATCH 6.1.y 1/5] i2c: core: Setup i2c_adapter runtime-pm before calling device_add()

[Sasha Levin]

From: Hans de Goede <hdegoede@redhat.com>

[ Upstream commit 60f68597024d5af727c8a5f5f3b11f246265192b ]

Platform glue code, which is not build into the kernel and thus cannot
use i2c_register_board_info() may want to use bus_register_notifier()
to listen for i2c-adapters to show up on which the platform code needs
to manually instantiate platform specific i2c_clients.

This results in calling i2c_new_client_device() from the bus notifier
which happens near the device_add() call.

If the i2c-core has not yet setup runtime-pm (specifically the
no-callbacks and ignore-children flags) for the device embedded
inside struct i2c_adapter and the driver for the i2c_client
calls pm_runtime_set_active() this will trigger the following
error inside __pm_runtime_set_status():

"runtime PM trying to activate child device %s but parent (%s) is not active\n"

and the i2c_client's runtime-status will not be updated.

Split the device_register() call for the adapter into device_initialize()
and device_add() and move the pm-runtime init calls inbetween these 2 calls
so that the runtime-status can be correctly set when a driver binds from
the bus-notifier.

Note the moved pm-runtime init calls just override the initial value of
some flags in struct device set by device_initialize() and calling these
before device_add() is safe.

Reviewed-by: Pali Rohár <pali@kernel.org>
Reviewed-by: Andi Shyti <andi.shyti@kernel.org>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
Stable-dep-of: 158efa411c57 ("i2c: core: fix adapter probe deferral loop")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/i2c/i2c-core-base.c | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
index f7e3fc0b3a1daa..c9b1818f7779a2 100644
--- a/drivers/i2c/i2c-core-base.c
+++ b/drivers/i2c/i2c-core-base.c
@@ -1553,7 +1553,18 @@ static int i2c_register_adapter(struct i2c_adapter *adap)
 	dev_set_name(&adap->dev, "i2c-%d", adap->nr);
 	adap->dev.bus = &i2c_bus_type;
 	adap->dev.type = &i2c_adapter_type;
-	res = device_register(&adap->dev);
+	device_initialize(&adap->dev);
+
+	/*
+	 * This adapter can be used as a parent immediately after device_add(),
+	 * setup runtime-pm (especially ignore-children) before hand.
+	 */
+	device_enable_async_suspend(&adap->dev);
+	pm_runtime_no_callbacks(&adap->dev);
+	pm_suspend_ignore_children(&adap->dev, true);
+	pm_runtime_enable(&adap->dev);
+
+	res = device_add(&adap->dev);
 	if (res) {
 		pr_err("adapter '%s': can't register device (%d)\n", adap->name, res);
 		goto out_list;
@@ -1565,11 +1576,6 @@ static int i2c_register_adapter(struct i2c_adapter *adap)
 	if (res)
 		goto out_reg;
 
-	device_enable_async_suspend(&adap->dev);
-	pm_runtime_no_callbacks(&adap->dev);
-	pm_suspend_ignore_children(&adap->dev, true);
-	pm_runtime_enable(&adap->dev);
-
 	res = i2c_init_recovery(adap);
 	if (res == -EPROBE_DEFER)
 		goto out_reg;
-- 
2.53.0

[PATCH 6.1.y 2/5] i2c: core: fix reference leak in i2c_register_adapter()

[Sasha Levin]

From: Joe Hattori <joe@pf.is.s.u-tokyo.ac.jp>

[ Upstream commit 3f8c4f5e9a57868fa107016c81165686d23325f2 ]

The reference count of the device incremented in device_initialize() is
not decremented when device_add() fails. Add a put_device() call before
returning from the function.

This bug was found by an experimental static analysis tool that I am
developing.

Fixes: 60f68597024d ("i2c: core: Setup i2c_adapter runtime-pm before calling device_add()")
Signed-off-by: Joe Hattori <joe@pf.is.s.u-tokyo.ac.jp>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Stable-dep-of: 158efa411c57 ("i2c: core: fix adapter probe deferral loop")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/i2c/i2c-core-base.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
index c9b1818f7779a2..f6e33bb3dd6e6e 100644
--- a/drivers/i2c/i2c-core-base.c
+++ b/drivers/i2c/i2c-core-base.c
@@ -1567,6 +1567,7 @@ static int i2c_register_adapter(struct i2c_adapter *adap)
 	res = device_add(&adap->dev);
 	if (res) {
 		pr_err("adapter '%s': can't register device (%d)\n", adap->name, res);
+		put_device(&adap->dev);
 		goto out_list;
 	}
 
-- 
2.53.0

[PATCH 6.1.y 3/5] i2c: core: fix irq domain leak on adapter registration failure

[Sasha Levin]

From: Johan Hovold <johan@kernel.org>

[ Upstream commit 8ce19524e4cc2462685f596a6402fbd8fb984ab2 ]

Make sure to tear down the host notify irq domain on adapter
registration failure to avoid leaking it.

This issue was flagged by Sashiko when reviewing another adapter
registration fix.

Fixes: 4d5538f5882a ("i2c: use an IRQ to report Host Notify events, not alert")
Cc: stable@vger.kernel.org	# 4.10
Cc: Benjamin Tissoires <bentiss@kernel.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Stable-dep-of: 158efa411c57 ("i2c: core: fix adapter probe deferral loop")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/i2c/i2c-core-base.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
index f6e33bb3dd6e6e..df2ded29788d1d 100644
--- a/drivers/i2c/i2c-core-base.c
+++ b/drivers/i2c/i2c-core-base.c
@@ -1568,7 +1568,7 @@ static int i2c_register_adapter(struct i2c_adapter *adap)
 	if (res) {
 		pr_err("adapter '%s': can't register device (%d)\n", adap->name, res);
 		put_device(&adap->dev);
-		goto out_list;
+		goto err_remove_irq_domain;
 	}
 
 	adap->debugfs = debugfs_create_dir(dev_name(&adap->dev), i2c_debugfs_root);
@@ -1611,6 +1611,8 @@ static int i2c_register_adapter(struct i2c_adapter *adap)
 	init_completion(&adap->dev_released);
 	device_unregister(&adap->dev);
 	wait_for_completion(&adap->dev_released);
+err_remove_irq_domain:
+	i2c_host_notify_irq_teardown(adap);
 out_list:
 	mutex_lock(&core_lock);
 	idr_remove(&i2c_adapter_idr, adap->nr);
-- 
2.53.0

[PATCH 6.1.y 4/5] i2c: core: fix NULL-deref on adapter registration failure

[Sasha Levin]

From: Johan Hovold <johan@kernel.org>

[ Upstream commit 2295d2bb101faa663fbc45fadbb3fec45f107441 ]

If adapter registration ever fails the release callback would trigger a
NULL-pointer dereference as the completion struct has not been
initialised.

Note that before the offending commit this would instead have resulted
in a minor memory leak of the adapter name.

Fixes: 3f8c4f5e9a57 ("i2c: core: fix reference leak in i2c_register_adapter()")
Cc: stable@vger.kernel.org
Cc: Joe Hattori <joe@pf.is.s.u-tokyo.ac.jp>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Stable-dep-of: 158efa411c57 ("i2c: core: fix adapter probe deferral loop")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/i2c/i2c-core-base.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
index df2ded29788d1d..e82607643ebfb4 100644
--- a/drivers/i2c/i2c-core-base.c
+++ b/drivers/i2c/i2c-core-base.c
@@ -1567,8 +1567,7 @@ static int i2c_register_adapter(struct i2c_adapter *adap)
 	res = device_add(&adap->dev);
 	if (res) {
 		pr_err("adapter '%s': can't register device (%d)\n", adap->name, res);
-		put_device(&adap->dev);
-		goto err_remove_irq_domain;
+		goto err_put_adap;
 	}
 
 	adap->debugfs = debugfs_create_dir(dev_name(&adap->dev), i2c_debugfs_root);
@@ -1608,10 +1607,12 @@ static int i2c_register_adapter(struct i2c_adapter *adap)
 
 out_reg:
 	debugfs_remove_recursive(adap->debugfs);
+	device_del(&adap->dev);
+err_put_adap:
 	init_completion(&adap->dev_released);
-	device_unregister(&adap->dev);
+	put_device(&adap->dev);
 	wait_for_completion(&adap->dev_released);
-err_remove_irq_domain:
+
 	i2c_host_notify_irq_teardown(adap);
 out_list:
 	mutex_lock(&core_lock);
-- 
2.53.0

[PATCH 6.1.y 5/5] i2c: core: fix adapter probe deferral loop

[Sasha Levin]

From: Johan Hovold <johan@kernel.org>

[ Upstream commit 158efa411c57111d87bf265a3776614f32d70007 ]

Drivers must not probe defer after having registered devices as that
will trigger a probe loop if the devices bind to a driver (cf. commit
fbc35b45f9f6 ("Add documentation on meaning of -EPROBE_DEFER")).

Move the recovery initialisation, where the GPIO lookup may fail, before
registering the adapter to prevent this.

Fixes: 75820314de26 ("i2c: core: add generic I2C GPIO recovery")
Cc: stable@vger.kernel.org	# 5.9
Cc: Codrin Ciubotariu <codrin.ciubotariu@microchip.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/i2c/i2c-core-base.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
index e82607643ebfb4..dd1b6d8779e210 100644
--- a/drivers/i2c/i2c-core-base.c
+++ b/drivers/i2c/i2c-core-base.c
@@ -1555,6 +1555,10 @@ static int i2c_register_adapter(struct i2c_adapter *adap)
 	adap->dev.type = &i2c_adapter_type;
 	device_initialize(&adap->dev);
 
+	res = i2c_init_recovery(adap);
+	if (res == -EPROBE_DEFER)
+		goto err_put_adap;
+
 	/*
 	 * This adapter can be used as a parent immediately after device_add(),
 	 * setup runtime-pm (especially ignore-children) before hand.
@@ -1576,10 +1580,6 @@ static int i2c_register_adapter(struct i2c_adapter *adap)
 	if (res)
 		goto out_reg;
 
-	res = i2c_init_recovery(adap);
-	if (res == -EPROBE_DEFER)
-		goto out_reg;
-
 	dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name);
 
 #ifdef CONFIG_I2C_COMPAT
-- 
2.53.0