[PATCH 11/21] HID: holtek: move FF initialization to .input_configured()

[Dmitry Torokhov]

The driver currently initializes force-feedback in its probe() function
after calling hid_hw_start() with HID_CONNECT_DEFAULT. This is racy as
the input device is already registered and visible to userspace at that
point.

Move the FF initialization to the .input_configured() callback to ensure
the device is fully prepared before registration.

Assisted-by: Gemini:gemini-3.1-pro
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
---
 drivers/hid/hid-holtekff.c | 46 +++++++++-------------------------------------
 1 file changed, 9 insertions(+), 37 deletions(-)

diff --git a/drivers/hid/hid-holtekff.c b/drivers/hid/hid-holtekff.c
index 32d08f7a660d..4834d42b2fa6 100644
--- a/drivers/hid/hid-holtekff.c
+++ b/drivers/hid/hid-holtekff.c
@@ -120,30 +120,24 @@ static int holtekff_play(struct input_dev *dev, void *data,
 	return 0;
 }
 
-static int holtekff_init(struct hid_device *hid)
+static int holtek_input_configured(struct hid_device *hid, struct hid_input *hidinput)
 {
 	struct holtekff_device *holtekff;
 	struct hid_report *report;
-	struct hid_input *hidinput;
 	struct list_head *report_list =
 			&hid->report_enum[HID_OUTPUT_REPORT].report_list;
-	struct input_dev *dev;
+	struct input_dev *dev = hidinput->input;
 	int error;
 
-	if (list_empty(&hid->inputs)) {
-		hid_err(hid, "no inputs found\n");
-		return -ENODEV;
-	}
-	hidinput = list_entry(hid->inputs.next, struct hid_input, list);
-	dev = hidinput->input;
+	if (!list_is_first(&hidinput->list, &hid->inputs))
+		return 0;
 
-	if (list_empty(report_list)) {
+	report = list_first_entry_or_null(report_list, struct hid_report, list);
+	if (!report) {
 		hid_err(hid, "no output report found\n");
 		return -ENODEV;
 	}
 
-	report = list_entry(report_list->next, struct hid_report, list);
-
 	if (report->maxfield < 1 || report->field[0]->report_count != 7) {
 		hid_err(hid, "unexpected output report layout\n");
 		return -ENODEV;
@@ -172,35 +166,13 @@ static int holtekff_init(struct hid_device *hid)
 	return 0;
 }
 #else
-static inline int holtekff_init(struct hid_device *hid)
+static inline int holtek_input_configured(struct hid_device *hid,
+					  struct hid_input *hidinput)
 {
 	return 0;
 }
 #endif
 
-static int holtek_probe(struct hid_device *hdev, const struct hid_device_id *id)
-{
-	int ret;
-
-	ret = hid_parse(hdev);
-	if (ret) {
-		hid_err(hdev, "parse failed\n");
-		goto err;
-	}
-
-	ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT & ~HID_CONNECT_FF);
-	if (ret) {
-		hid_err(hdev, "hw start failed\n");
-		goto err;
-	}
-
-	holtekff_init(hdev);
-
-	return 0;
-err:
-	return ret;
-}
-
 static const struct hid_device_id holtek_devices[] = {
 	{ HID_USB_DEVICE(USB_VENDOR_ID_HOLTEK, USB_DEVICE_ID_HOLTEK_ON_LINE_GRIP) },
 	{ }
@@ -210,7 +182,7 @@ MODULE_DEVICE_TABLE(hid, holtek_devices);
 static struct hid_driver holtek_driver = {
 	.name = "holtek",
 	.id_table = holtek_devices,
-	.probe = holtek_probe,
+	.input_configured = holtek_input_configured,
 };
 module_hid_driver(holtek_driver);
 

-- 
2.55.0.629.g250fe7f194-goog