[PATCH v2 03/33] HID: logitech-hidpp: drain G920 FF workqueue before closing transport

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

Probe no longer keeps the HID transport open indefinitely, so the
underlying USB interrupt IN endpoint only stays active while the HID
transport is held open. When the last input user closes the device
after input core flushes active effects, or when the device is
inhibited with commands still queued, releasing the HID transport
shuts down transport I/O unless another client holds it open. Queued
force-feedback commands then fail to receive their HID++ replies,
causing command timeouts and leaving stale slot mappings behind.

Override the input open and close callbacks once G920 force feedback is
initialized so the force-feedback send queue drains completely before
closing the HID transport.

Fixes: 91cf9a98ae41 ("HID: logitech-hidpp: make .probe usbhid capable")
Tested-by: Gideon Heinz <gideonheinz02@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
---
 drivers/hid/hid-logitech-hidpp.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/drivers/hid/hid-logitech-hidpp.c b/drivers/hid/hid-logitech-hidpp.c
index d9342a3e8122..d5f53b35ac6f 100644
--- a/drivers/hid/hid-logitech-hidpp.c
+++ b/drivers/hid/hid-logitech-hidpp.c
@@ -2815,6 +2815,22 @@ static void hidpp_ff_destroy(struct ff_device *ff)
 	kfree(data->effect_ids);
 }
 
+static int g920_input_open(struct input_dev *dev)
+{
+	struct hid_device *hid = input_get_drvdata(dev);
+
+	return hid_hw_open(hid);
+}
+
+static void g920_input_close(struct input_dev *dev)
+{
+	struct hid_device *hid = input_get_drvdata(dev);
+	struct hidpp_ff_private_data *data = dev->ff->private;
+
+	flush_workqueue(data->wq);
+	hid_hw_close(hid);
+}
+
 static int hidpp_ff_init(struct hidpp_device *hidpp,
 			 struct hidpp_ff_private_data *data)
 {
@@ -2897,6 +2913,9 @@ static int hidpp_ff_init(struct hidpp_device *hidpp,
 	ff->set_autocenter = hidpp_ff_set_autocenter;
 	ff->destroy = hidpp_ff_destroy;
 
+	dev->open = g920_input_open;
+	dev->close = g920_input_close;
+
 	/* Create sysfs interface */
 	error = device_create_file(&(hidpp->hid_dev->dev), &dev_attr_range);
 	if (error)

-- 
2.56.0.542.g3ef89b7020-goog