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From:   Sonny Sasaka <sonnysasaka@chromium.org>
To:     linux-bluetooth@vger.kernel.org
Cc:     Sonny Sasaka <sonnysasaka@chromium.org>,
        Archie Pusaka <apusaka@chromium.org>
Subject: [PATCH BlueZ] input/device: Unregister all UHID event listeners at UHID_DESTROY
Date:   Thu, 20 Aug 2020 21:35:36 -0700
Message-Id: <20200821043536.15332-1-sonnysasaka@chromium.org>
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Sender: linux-bluetooth-owner@vger.kernel.org
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When destroying UHID, we should also unregister all event listeners so
that they don't get double registered at reconnection. It fixes a bug
where battery report is not available to kernel after reconnection and
also prevents memory leak.

Tested with Logitech M535 mouse:
* Connect mouse to the device running BlueZ
* cat /sys/class/power_supply/hid-{addr}-battery/capacity # works
* Disconnect mouse
* Reconnect mouse
* cat /sys/class/power_supply/hid-{addr}-battery/capacity # still works

Reviewed-by: Archie Pusaka <apusaka@chromium.org>

---
 profiles/input/device.c | 2 ++
 src/shared/uhid.c       | 9 +++++++++
 src/shared/uhid.h       | 1 +
 3 files changed, 12 insertions(+)

diff --git a/profiles/input/device.c b/profiles/input/device.c
index 8fc04be37..f6823b7b6 100644
--- a/profiles/input/device.c
+++ b/profiles/input/device.c
@@ -982,6 +982,8 @@ static int uhid_disconnect(struct input_device *idev)
 	if (!idev->uhid_created)
 		return 0;
 
+	bt_uhid_unregister_all(idev->uhid);
+
 	memset(&ev, 0, sizeof(ev));
 	ev.type = UHID_DESTROY;
 
diff --git a/src/shared/uhid.c b/src/shared/uhid.c
index 685f90243..71a4e04ba 100644
--- a/src/shared/uhid.c
+++ b/src/shared/uhid.c
@@ -219,6 +219,15 @@ bool bt_uhid_unregister(struct bt_uhid *uhid, unsigned int id)
 	return true;
 }
 
+bool bt_uhid_unregister_all(struct bt_uhid *uhid)
+{
+	if (!uhid)
+		return false;
+
+	queue_remove_all(uhid->notify_list, NULL, NULL, free);
+	return true;
+}
+
 int bt_uhid_send(struct bt_uhid *uhid, const struct uhid_event *ev)
 {
 	ssize_t len;
diff --git a/src/shared/uhid.h b/src/shared/uhid.h
index 459a24900..dbdca852d 100644
--- a/src/shared/uhid.h
+++ b/src/shared/uhid.h
@@ -40,5 +40,6 @@ typedef void (*bt_uhid_callback_t)(struct uhid_event *ev, void *user_data);
 unsigned int bt_uhid_register(struct bt_uhid *uhid, uint32_t event,
 				bt_uhid_callback_t func, void *user_data);
 bool bt_uhid_unregister(struct bt_uhid *uhid, unsigned int id);
+bool bt_uhid_unregister_all(struct bt_uhid *uhid);
 
 int bt_uhid_send(struct bt_uhid *uhid, const struct uhid_event *ev);
-- 
2.26.2