[PATCH v3 02/12] HID: logitech-hidpp: Revert "Don't restart communication if not necessary"

[Hans de Goede <hdegoede@redhat.com>]

Commit 91cf9a98ae41 ("HID: logitech-hidpp: make .probe usbhid capable")
makes hidpp_probe() first call hid_hw_start(hdev, 0) to allow IO
without connecting any hid subdrivers (hid-input, hidraw).

This is done to allow to retrieve the device's name and serial number
and store these in hdev->name and hdev->uniq.

Then later on IO was stopped and started again with hid_hw_start(hdev,
HID_CONNECT_DEFAULT) connecting hid-input and hidraw after the name
and serial number have been setup.

Commit 498ba2069035 ("HID: logitech-hidpp: Don't restart communication
if not necessary") changed the probe() code to only do the start with
a 0 connect-mask + restart later for unifying devices.

But for non unifying devices hdev->name and hdev->uniq are updated too.
So this change re-introduces the problem for which the start with
a 0 connect-mask + restart later behavior was introduced.

The previous patch in this series changes the unifying path to instead of
restarting IO only call hid_connect() later. This avoids possible issues
with restarting IO seen on non unifying devices.

Revert the change to limit the restart behavior to unifying devices to
fix hdev->name changing after userspace facing devices have already been
registered.

This series has been tested on the following devices:
Logitech Bluetooth Laser Travel Mouse (bluetooth, HID++ 1.0)
Logitech M720 Triathlon (bluetooth, HID++ 4.5)
Logitech M720 Triathlon (unifying, HID++ 4.5)
Logitech K400 Pro (unifying, HID++ 4.1)
Logitech K270 (eQUAD nano Lite, HID++ 2.0)
Logitech M185 (eQUAD nano Lite, HID++ 4.5)
Logitech LX501 keyboard (27 Mhz, HID++ builtin scroll-wheel, HID++ 1.0)
Logitech M-RAZ105 mouse (27 Mhz, HID++ extra mouse buttons, HID++ 1.0)

Fixes: 498ba2069035 ("HID: logitech-hidpp: Don't restart communication if not necessary")
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 drivers/hid/hid-logitech-hidpp.c | 24 ++++++++----------------
 1 file changed, 8 insertions(+), 16 deletions(-)

diff --git a/drivers/hid/hid-logitech-hidpp.c b/drivers/hid/hid-logitech-hidpp.c
index aa4f232c4518..c582d19b11d6 100644
--- a/drivers/hid/hid-logitech-hidpp.c
+++ b/drivers/hid/hid-logitech-hidpp.c
@@ -4394,7 +4394,6 @@ static int hidpp_probe(struct hid_device *hdev, const struct hid_device_id *id)
 	bool connected;
 	unsigned int connect_mask = HID_CONNECT_DEFAULT;
 	struct hidpp_ff_private_data data;
-	bool will_restart = false;
 
 	/* report_fixup needs drvdata to be set before we call hid_parse */
 	hidpp = devm_kzalloc(&hdev->dev, sizeof(*hidpp), GFP_KERNEL);
@@ -4445,10 +4444,6 @@ static int hidpp_probe(struct hid_device *hdev, const struct hid_device_id *id)
 			return ret;
 	}
 
-	if (hidpp->quirks & HIDPP_QUIRK_DELAYED_INIT ||
-	    hidpp->quirks & HIDPP_QUIRK_UNIFYING)
-		will_restart = true;
-
 	INIT_WORK(&hidpp->work, delayed_work_cb);
 	mutex_init(&hidpp->send_mutex);
 	init_waitqueue_head(&hidpp->wait);
@@ -4465,7 +4460,7 @@ static int hidpp_probe(struct hid_device *hdev, const struct hid_device_id *id)
 	 * name and serial number and store these in hdev->name and hdev->uniq,
 	 * before the hid-input and hidraw drivers expose these to userspace.
 	 */
-	ret = hid_hw_start(hdev, will_restart ? 0 : connect_mask);
+	ret = hid_hw_start(hdev, 0);
 	if (ret) {
 		hid_err(hdev, "hw start failed\n");
 		goto hid_hw_start_fail;
@@ -4504,7 +4499,6 @@ static int hidpp_probe(struct hid_device *hdev, const struct hid_device_id *id)
 			hidpp->wireless_feature_index = 0;
 		else if (ret)
 			goto hid_hw_init_fail;
-		ret = 0;
 	}
 
 	if (connected && (hidpp->quirks & HIDPP_QUIRK_CLASS_WTP)) {
@@ -4520,16 +4514,14 @@ static int hidpp_probe(struct hid_device *hdev, const struct hid_device_id *id)
 	schedule_work(&hidpp->work);
 	flush_work(&hidpp->work);
 
-	if (will_restart) {
-		if (hidpp->quirks & HIDPP_QUIRK_DELAYED_INIT)
-			connect_mask &= ~HID_CONNECT_HIDINPUT;
+	if (hidpp->quirks & HIDPP_QUIRK_DELAYED_INIT)
+		connect_mask &= ~HID_CONNECT_HIDINPUT;
 
-		/* Now export the actual inputs and hidraw nodes to the world */
-		ret = hid_connect(hdev, connect_mask);
-		if (ret) {
-			hid_err(hdev, "%s:hid_connect returned error %d\n", __func__, ret);
-			goto hid_hw_init_fail;
-		}
+	/* Now export the actual inputs and hidraw nodes to the world */
+	ret = hid_connect(hdev, connect_mask);
+	if (ret) {
+		hid_err(hdev, "%s:hid_connect returned error %d\n", __func__, ret);
+		goto hid_hw_init_fail;
 	}
 
 	if (hidpp->quirks & HIDPP_QUIRK_CLASS_G920) {
-- 
2.41.0