Patch "HID: hid-steam: Move hidraw input (un)registering to work" has been added to the 6.6-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    HID: hid-steam: Move hidraw input (un)registering to work

to the 6.6-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     hid-hid-steam-move-hidraw-input-un-registering-to-wo.patch
and it can be found in the queue-6.6 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 9e2f8177b284e249ae0a53a5658c6e41bedb7d9e
Author: Vicki Pfau <vi@xxxxxxxxxxx>
Date:   Tue Feb 4 19:55:27 2025 -0800

    HID: hid-steam: Move hidraw input (un)registering to work
    
    [ Upstream commit 79504249d7e27cad4a3eeb9afc6386e418728ce0 ]
    
    Due to an interplay between locking in the input and hid transport subsystems,
    attempting to register or deregister the relevant input devices during the
    hidraw open/close events can lead to a lock ordering issue. Though this
    shouldn't cause a deadlock, this commit moves the input device manipulation to
    deferred work to sidestep the issue.
    
    Fixes: 385a4886778f6 ("HID: steam: remove input device when a hid client is running.")
    Signed-off-by: Vicki Pfau <vi@xxxxxxxxxxx>
    Signed-off-by: Jiri Kosina <jkosina@xxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/hid/hid-steam.c b/drivers/hid/hid-steam.c
index a25d0034dc1ea..ee3c27e133443 100644
--- a/drivers/hid/hid-steam.c
+++ b/drivers/hid/hid-steam.c
@@ -312,6 +312,7 @@ struct steam_device {
 	u16 rumble_left;
 	u16 rumble_right;
 	unsigned int sensor_timestamp_us;
+	struct work_struct unregister_work;
 };
 
 static int steam_recv_report(struct steam_device *steam,
@@ -1070,6 +1071,31 @@ static void steam_mode_switch_cb(struct work_struct *work)
 	}
 }
 
+static void steam_work_unregister_cb(struct work_struct *work)
+{
+	struct steam_device *steam = container_of(work, struct steam_device,
+							unregister_work);
+	unsigned long flags;
+	bool connected;
+	bool opened;
+
+	spin_lock_irqsave(&steam->lock, flags);
+	opened = steam->client_opened;
+	connected = steam->connected;
+	spin_unlock_irqrestore(&steam->lock, flags);
+
+	if (connected) {
+		if (opened) {
+			steam_sensors_unregister(steam);
+			steam_input_unregister(steam);
+		} else {
+			steam_set_lizard_mode(steam, lizard_mode);
+			steam_input_register(steam);
+			steam_sensors_register(steam);
+		}
+	}
+}
+
 static bool steam_is_valve_interface(struct hid_device *hdev)
 {
 	struct hid_report_enum *rep_enum;
@@ -1115,8 +1141,7 @@ static int steam_client_ll_open(struct hid_device *hdev)
 	steam->client_opened = true;
 	spin_unlock_irqrestore(&steam->lock, flags);
 
-	steam_sensors_unregister(steam);
-	steam_input_unregister(steam);
+	schedule_work(&steam->unregister_work);
 
 	return 0;
 }
@@ -1133,11 +1158,7 @@ static void steam_client_ll_close(struct hid_device *hdev)
 	connected = steam->connected && !steam->client_opened;
 	spin_unlock_irqrestore(&steam->lock, flags);
 
-	if (connected) {
-		steam_set_lizard_mode(steam, lizard_mode);
-		steam_input_register(steam);
-		steam_sensors_register(steam);
-	}
+	schedule_work(&steam->unregister_work);
 }
 
 static int steam_client_ll_raw_request(struct hid_device *hdev,
@@ -1229,6 +1250,7 @@ static int steam_probe(struct hid_device *hdev,
 	INIT_LIST_HEAD(&steam->list);
 	INIT_WORK(&steam->rumble_work, steam_haptic_rumble_cb);
 	steam->sensor_timestamp_us = 0;
+	INIT_WORK(&steam->unregister_work, steam_work_unregister_cb);
 
 	/*
 	 * With the real steam controller interface, do not connect hidraw.
@@ -1289,6 +1311,7 @@ static int steam_probe(struct hid_device *hdev,
 	cancel_work_sync(&steam->work_connect);
 	cancel_delayed_work_sync(&steam->mode_switch);
 	cancel_work_sync(&steam->rumble_work);
+	cancel_work_sync(&steam->unregister_work);
 
 	return ret;
 }
@@ -1305,6 +1328,7 @@ static void steam_remove(struct hid_device *hdev)
 	cancel_delayed_work_sync(&steam->mode_switch);
 	cancel_work_sync(&steam->work_connect);
 	cancel_work_sync(&steam->rumble_work);
+	cancel_work_sync(&steam->unregister_work);
 	hid_destroy_device(steam->client_hdev);
 	steam->client_hdev = NULL;
 	steam->client_opened = false;