[PATCH v5 07/11] HID: steam: Rearrange teardown sequence

[Vicki Pfau <vi@endrift.com>]

This fixes a narrow window during the teardown sequence where callbacks
could still be scheduled during cleanup that would then have a dangling
pointer to the now-freed steam struct.

This also puts work canceling for rumble and mode switch in
steam_unregister, as that shouldn't persist while the client hdev is open.

Signed-off-by: Vicki Pfau <vi@endrift.com>
---
 drivers/hid/hid-steam.c | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/drivers/hid/hid-steam.c b/drivers/hid/hid-steam.c
index 12203d61922f..663fda8a86fd 100644
--- a/drivers/hid/hid-steam.c
+++ b/drivers/hid/hid-steam.c
@@ -1156,6 +1156,9 @@ static void steam_unregister(struct steam_device *steam)
 	steam_battery_unregister(steam);
 	steam_sensors_unregister(steam);
 	steam_input_unregister(steam);
+	cancel_work_sync(&steam->rumble_work);
+	cancel_delayed_work_sync(&steam->mode_switch);
+	cancel_delayed_work_sync(&steam->coalesce_rumble_work);
 	mutex_lock(&steam_devices_lock);
 	list_del_init(&steam->list);
 	mutex_unlock(&steam_devices_lock);
@@ -1441,25 +1444,24 @@ static int steam_probe(struct hid_device *hdev,
 static void steam_remove(struct hid_device *hdev)
 {
 	struct steam_device *steam = hid_get_drvdata(hdev);
+	unsigned long flags;
 
 	if (!steam || hdev->group == HID_GROUP_STEAM) {
 		hid_hw_stop(hdev);
 		return;
 	}
 
+	hid_hw_close(hdev);
 	hid_destroy_device(steam->client_hdev);
-	cancel_delayed_work_sync(&steam->mode_switch);
-	cancel_work_sync(&steam->work_connect);
-	cancel_work_sync(&steam->rumble_work);
-	cancel_delayed_work_sync(&steam->coalesce_rumble_work);
-	steam->client_hdev = NULL;
+	spin_lock_irqsave(&steam->lock, flags);
 	steam->client_opened = 0;
+	spin_unlock_irqrestore(&steam->lock, flags);
+	cancel_work_sync(&steam->work_connect);
 	if (steam->quirks & STEAM_QUIRK_WIRELESS) {
 		hid_info(hdev, "Steam wireless receiver disconnected");
 	}
-	hid_hw_close(hdev);
-	hid_hw_stop(hdev);
 	steam_unregister(steam);
+	hid_hw_stop(hdev);
 }
 
 static void steam_do_connect_event(struct steam_device *steam, bool connected)
-- 
2.54.0