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Date:   Tue, 28 Nov 2023 22:17:56 +0000
Mime-Version: 1.0
Message-ID: <20231128221756.2591158-1-royluo@google.com>
Subject: [PATCH v3] USB: gadget: core: adjust uevent timing on gadget unbind
From:   Roy Luo <royluo@google.com>
To:     royluo@google.com, gregkh@linuxfoundation.org,
        stern@rowland.harvard.edu, badhri@google.com,
        quic_kriskura@quicinc.com, francesco.dolcini@toradex.com,
        quic_eserrao@quicinc.com, ivan.orlov0322@gmail.com,
        linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org
Cc:     stable@vger.kernel.org
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

The KOBJ_CHANGE uevent is sent before gadget unbind is actually
executed, resulting in inaccurate uevent emitted at incorrect timing
(the uevent would have USB_UDC_DRIVER variable set while it would
soon be removed).
Move the KOBJ_CHANGE uevent to the end of the unbind function so that
uevent is sent only after the change has been made.

Fixes: 2ccea03a8f7e ("usb: gadget: introduce UDC Class")
Cc: stable@vger.kernel.org
Signed-off-by: Roy Luo <royluo@google.com>
---
Changes since v1: add Fixes tag
Changes since v2: add cc stable@vger.kernel.org
---
 drivers/usb/gadget/udc/core.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/gadget/udc/core.c b/drivers/usb/gadget/udc/core.c
index ded9531f141b..d59f94464b87 100644
--- a/drivers/usb/gadget/udc/core.c
+++ b/drivers/usb/gadget/udc/core.c
@@ -1646,8 +1646,6 @@ static void gadget_unbind_driver(struct device *dev)
 
 	dev_dbg(&udc->dev, "unbinding gadget driver [%s]\n", driver->function);
 
-	kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE);
-
 	udc->allow_connect = false;
 	cancel_work_sync(&udc->vbus_work);
 	mutex_lock(&udc->connect_lock);
@@ -1667,6 +1665,8 @@ static void gadget_unbind_driver(struct device *dev)
 	driver->is_bound = false;
 	udc->driver = NULL;
 	mutex_unlock(&udc_lock);
+
+	kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE);
 }
 
 /* ------------------------------------------------------------------------- */

base-commit: 9b6de136b5f0158c60844f85286a593cb70fb364
-- 
2.43.0.rc1.413.gea7ed67945-goog