FAILED: patch "[PATCH] Bluetooth: fix debugfs registration" failed to apply to 4.19-stable tree

The patch below does not apply to the 4.19-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 <[email protected]>.

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-4.19.y
git checkout FETCH_HEAD
git cherry-pick -x fe2ccc6c29d53e14d3c8b3ddf8ad965a92e074ee
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2023061109-dropbox-cattle-a47d@gregkh' --subject-prefix 'PATCH 4.19.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

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

From fe2ccc6c29d53e14d3c8b3ddf8ad965a92e074ee Mon Sep 17 00:00:00 2001
From: Johan Hovold <[email protected]>
Date: Wed, 31 May 2023 10:57:58 +0200
Subject: [PATCH] Bluetooth: fix debugfs registration

Since commit ec6cef9cd98d ("Bluetooth: Fix SMP channel registration for unconfigured controllers") the debugfs interface for unconfigured controllers will be created when the controller is configured.

There is however currently nothing preventing a controller from being configured multiple time (e.g. setting the device address using btmgmt) which results in failed attempts to register the already registered debugfs entries:

debugfs: File 'features' in directory 'hci0' already present!
debugfs: File 'manufacturer' in directory 'hci0' already present!
debugfs: File 'hci_version' in directory 'hci0' already present!
...
debugfs: File 'quirk_simultaneous_discovery' in directory 'hci0' already present!

Add a controller flag to avoid trying to register the debugfs interface more than once.

index 07df96c47ef4..872dcb91a540 100644
@@ -350,6 +350,7 @@ enum {
 enum {
 	HCI_SETUP,
 	HCI_CONFIG,
+	HCI_DEBUGFS_CREATED,
 	HCI_AUTO_OFF,
 	HCI_RFKILLED,
 	HCI_MGMT,

index a59695f04c25..804cde43b4e0 100644
@@ -4551,6 +4551,9 @@ static int hci_init_sync(struct hci_dev *hdev)
 	    !hci_dev_test_flag(hdev, HCI_CONFIG))
 		return 0;
 
+	if (hci_dev_test_and_set_flag(hdev, HCI_DEBUGFS_CREATED))
+		return 0;
+
 	hci_debugfs_create_common(hdev);
 
 	if (lmp_bredr_capable(hdev))