From 589e5060206b97a9602534d19d53264d35cd969f Mon Sep 17 00:00:00 2001 From: Benjamin Tissoires Date: Wed, 13 Jul 2016 18:06:11 +0200 Subject: [PATCH] HID: wacom: leds: actually release the LEDs on disconnect There is a bug (?) in devm_led_classdev_register() in which its increments the refcount of the parent. If the parent is an input device, that means the ref count never reaches 0 when devm_input_device_release() gets called. This means that the LEDs and all the devres resources attached to the input device are not released. Manually force the release of the group so that the leds are released once we are done using them. Signed-off-by: Benjamin Tissoires Acked-by: Ping Cheng Signed-off-by: Jiri Kosina --- drivers/hid/wacom.h | 1 + drivers/hid/wacom_sys.c | 27 ++++++++++++++++++++++++++- 2 files changed, 27 insertions(+), 1 deletion(-) diff --git a/drivers/hid/wacom.h b/drivers/hid/wacom.h index 0c498c46de5f..9159dd3e4b90 100644 --- a/drivers/hid/wacom.h +++ b/drivers/hid/wacom.h @@ -130,6 +130,7 @@ struct wacom_group_leds { u8 select; /* status led selector (0..3) */ struct wacom_led *leds; unsigned int count; + struct device *dev; }; struct wacom_battery { diff --git a/drivers/hid/wacom_sys.c b/drivers/hid/wacom_sys.c index c5d518da0d0f..3a651e288776 100644 --- a/drivers/hid/wacom_sys.c +++ b/drivers/hid/wacom_sys.c @@ -1068,6 +1068,13 @@ static int wacom_led_register_one(struct device *dev, struct wacom *wacom, return 0; } +static void wacom_led_groups_release_one(void *data) +{ + struct wacom_group_leds *group = data; + + devres_release_group(group->dev, group); +} + static int wacom_led_groups_alloc_and_register_one(struct device *dev, struct wacom *wacom, int group_id, int count, @@ -1098,7 +1105,25 @@ static int wacom_led_groups_alloc_and_register_one(struct device *dev, goto err; } - devres_remove_group(dev, &wacom->led.groups[group_id]); + wacom->led.groups[group_id].dev = dev; + + devres_close_group(dev, &wacom->led.groups[group_id]); + + /* + * There is a bug (?) in devm_led_classdev_register() in which its + * increments the refcount of the parent. If the parent is an input + * device, that means the ref count never reaches 0 when + * devm_input_device_release() gets called. + * This means that the LEDs are still there after disconnect. + * Manually force the release of the group so that the leds are released + * once we are done using them. + */ + error = devm_add_action_or_reset(&wacom->hdev->dev, + wacom_led_groups_release_one, + &wacom->led.groups[group_id]); + if (error) + return error; + return 0; err: -- 2.20.1