FAILED: patch "[PATCH] usb: gadget: core: flush gadget workqueue after device" failed to apply to 5.4-stable tree

FAILED: patch "[PATCH] usb: gadget: core: flush gadget workqueue after device" failed to apply to 5.4-stable tree

[gregkh]

The patch below does not apply to the 5.4-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-5.4.y
git checkout FETCH_HEAD
git cherry-pick -x 399a45e5237ca14037120b1b895bd38a3b4492ea
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2025021848-sixtieth-living-e034@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^..

Possible dependencies:



thanks,

greg k-h

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

From 399a45e5237ca14037120b1b895bd38a3b4492ea Mon Sep 17 00:00:00 2001
From: Roy Luo <royluo@google.com>
Date: Tue, 4 Feb 2025 23:36:42 +0000
Subject: [PATCH] usb: gadget: core: flush gadget workqueue after device
 removal

device_del() can lead to new work being scheduled in gadget->work
workqueue. This is observed, for example, with the dwc3 driver with the
following call stack:
  device_del()
    gadget_unbind_driver()
      usb_gadget_disconnect_locked()
        dwc3_gadget_pullup()
	  dwc3_gadget_soft_disconnect()
	    usb_gadget_set_state()
	      schedule_work(&gadget->work)

Move flush_work() after device_del() to ensure the workqueue is cleaned
up.

Fixes: 5702f75375aa9 ("usb: gadget: udc-core: move sysfs_notify() to a workqueue")
Cc: stable <stable@kernel.org>
Signed-off-by: Roy Luo <royluo@google.com>
Reviewed-by: Alan Stern <stern@rowland.harvard.edu>
Reviewed-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Link: https://lore.kernel.org/r/20250204233642.666991-1-royluo@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/gadget/udc/core.c b/drivers/usb/gadget/udc/core.c
index a6f46364be65..4b3d5075621a 100644
--- a/drivers/usb/gadget/udc/core.c
+++ b/drivers/usb/gadget/udc/core.c
@@ -1543,8 +1543,8 @@ void usb_del_gadget(struct usb_gadget *gadget)
 
 	kobject_uevent(&udc->dev.kobj, KOBJ_REMOVE);
 	sysfs_remove_link(&udc->dev.kobj, "gadget");
-	flush_work(&gadget->work);
 	device_del(&gadget->dev);
+	flush_work(&gadget->work);
 	ida_free(&gadget_id_numbers, gadget->id_number);
 	cancel_work_sync(&udc->vbus_work);
 	device_unregister(&udc->dev);