From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: stable@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	patches@lists.linux.dev,
	Jose Javier Rodriguez Barbarin <dev-josejavier.rodriguez@duagon.com>,
	Johannes Thumshirn <morbidrsa@gmail.com>,
	Sasha Levin <sashal@kernel.org>
Subject: [PATCH 6.18 482/641] mcb: fix incorrect sanity check
Date: Tue, 24 Feb 2026 17:23:28 -0800
Message-ID: <20260225012400.201183724@linuxfoundation.org>
In-Reply-To: <20260225012348.915798704@linuxfoundation.org>
References: <20260225012348.915798704@linuxfoundation.org>
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6.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Jose Javier Rodriguez Barbarin <dev-josejavier.rodriguez@duagon.com>

[ Upstream commit bc2e4bc952e26dd93b978588219044bd8b24237b ]

__mcb_register_driver() makes some sanity checks over mcb_driver
to check if .probe and .remove callbacks are set.  However, since commit
3bd13ae04ccc ("gpio: menz127: simplify error path and remove remove()")
removed the .remove callback from menz127-gpio.c, not all mcb device
drivers implement .remove callback.

Remove .remove check to ensure all mcb device drivers can be loaded.

Signed-off-by: Jose Javier Rodriguez Barbarin <dev-josejavier.rodriguez@duagon.com>
Fixes: 3bd13ae04ccc ("gpio: menz127: simplify error path and remove remove()")
[ jth: added statement about menz127-gpio.c ]
Signed-off-by: Johannes Thumshirn <morbidrsa@gmail.com>
Link: https://patch.msgid.link/16fb55bd59d9c1d2ce2443f41d4dec2048f9a8ec.1768562302.git.jth@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/mcb/mcb-core.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/mcb/mcb-core.c b/drivers/mcb/mcb-core.c
index c1367223e71a0..3d487d75c483d 100644
--- a/drivers/mcb/mcb-core.c
+++ b/drivers/mcb/mcb-core.c
@@ -85,7 +85,8 @@ static void mcb_remove(struct device *dev)
 	struct mcb_device *mdev = to_mcb_device(dev);
 	struct module *carrier_mod;
 
-	mdrv->remove(mdev);
+	if (mdrv->remove)
+		mdrv->remove(mdev);
 
 	carrier_mod = mdev->dev.parent->driver->owner;
 	module_put(carrier_mod);
@@ -176,13 +177,13 @@ static const struct device_type mcb_carrier_device_type = {
  * @owner: The @mcb_driver's module
  * @mod_name: The name of the @mcb_driver's module
  *
- * Register a @mcb_driver at the system. Perform some sanity checks, if
- * the .probe and .remove methods are provided by the driver.
+ * Register a @mcb_driver at the system. Perform a sanity check, if
+ * .probe method is provided by the driver.
  */
 int __mcb_register_driver(struct mcb_driver *drv, struct module *owner,
 			const char *mod_name)
 {
-	if (!drv->probe || !drv->remove)
+	if (!drv->probe)
 		return -EINVAL;
 
 	drv->driver.owner = owner;
-- 
2.51.0