[PATCH 07/10] HID: hid-lenovo-go-s: Move attribute init to after device query

[Derek J. Clark]

Currently this driver registers attributes before the MCU is ready to
accept commands. This can lead to attribute access that blocks the MCU
in some rare cases.

Move attribute construction to gos_cfg_setup, after the device has been
queried. Gate creation to drvdata.gp_registered and
drvdata.rgb_registered so a resume before setup has run doesn't prevent
attribute creation or attempt to re-register the same attributes.

Fixes: a23f3497bf208c59ad ("HID: hid-lenovo-go-s: Add Lenovo Legion Go S Series HID Driver")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Derek J. Clark <derekjohn.clark@xxxxxxxxx>
---
 drivers/hid/hid-lenovo-go-s.c | 68 +++++++++++++++++++++++------------
 1 file changed, 45 insertions(+), 23 deletions(-)

diff --git a/drivers/hid/hid-lenovo-go-s.c b/drivers/hid/hid-lenovo-go-s.c
index 6d98fff6d987..f1a0bcfcdb71 100644
--- a/drivers/hid/hid-lenovo-go-s.c
+++ b/drivers/hid/hid-lenovo-go-s.c
@@ -1452,6 +1452,7 @@ static struct led_classdev_mc gos_cdev_rgb = {
 
 static void cfg_setup(struct work_struct *work)
 {
+	bool gp_registered, rgb_registered;
 	int ret;
 
 	/* MCU */
@@ -1497,10 +1498,53 @@ static void cfg_setup(struct work_struct *work)
 		return;
 	}
 
+	/* Pairs with smp_store_release from below */
+	gp_registered = smp_load_acquire(&drvdata.gp_registered);
+	if (gp_registered)
+		goto try_rgb;
+
+	ret = sysfs_create_groups(&drvdata.hdev->dev.kobj, top_level_attr_groups);
+	if (ret) {
+		dev_err(&drvdata.hdev->dev,
+			"Failed to create gamepad configuration attributes: %i\n", ret);
+		goto try_rgb;
+	}
+
 	/* Pairs with smp_load_acquire in attribute show/store functions */
 	smp_store_release(&drvdata.gp_registered, true);
+	gp_registered = true;
+
+try_rgb:
+	/* Pairs with smp_store_release from below */
+	rgb_registered = smp_load_acquire(&drvdata.rgb_registered);
+	if (rgb_registered)
+		goto update_kobjects;
+
+	ret = devm_led_classdev_multicolor_register(&drvdata.hdev->dev, &gos_cdev_rgb);
+	if (ret) {
+		dev_err(&drvdata.hdev->dev,
+			"Failed to create RGB device: %i\n", ret);
+		goto update_kobjects;
+	}
+
+	ret = devm_device_add_group(gos_cdev_rgb.led_cdev.dev, &rgb_attr_group);
+	if (ret) {
+		dev_err(&drvdata.hdev->dev,
+			"Failed to create RGB configuration attributes: %i\n", ret);
+		goto update_kobjects;
+	}
+
+	drvdata.led_cdev = &gos_cdev_rgb.led_cdev;
+
 	/* Pairs with smp_load_acquire in attribute show/store functions */
 	smp_store_release(&drvdata.rgb_registered, true);
+	rgb_registered = true;
+
+update_kobjects:
+	if (gp_registered)
+		kobject_uevent(&drvdata.hdev->dev.kobj, KOBJ_CHANGE);
+	if (rgb_registered)
+		kobject_uevent(&drvdata.led_cdev->dev->kobj, KOBJ_CHANGE);
 }
 
 static int hid_gos_cfg_probe(struct hid_device *hdev,
@@ -1510,30 +1554,8 @@ static int hid_gos_cfg_probe(struct hid_device *hdev,
 
 	hid_set_drvdata(hdev, &drvdata);
 	drvdata.hdev = hdev;
-	mutex_init(&drvdata.cfg_mutex);
-
-	ret = sysfs_create_groups(&hdev->dev.kobj, top_level_attr_groups);
-	if (ret) {
-		dev_err_probe(&hdev->dev, ret,
-			      "Failed to create gamepad configuration attributes\n");
-		return ret;
-	}
-
-	ret = devm_led_classdev_multicolor_register(&hdev->dev, &gos_cdev_rgb);
-	if (ret) {
-		dev_err_probe(&hdev->dev, ret, "Failed to create RGB device\n");
-		return ret;
-	}
-
-	ret = devm_device_add_group(gos_cdev_rgb.led_cdev.dev, &rgb_attr_group);
-	if (ret) {
-		dev_err_probe(&hdev->dev, ret,
-			      "Failed to create RGB configuration attributes\n");
-		return ret;
-	}
-
-	drvdata.led_cdev = &gos_cdev_rgb.led_cdev;
 
+	mutex_init(&drvdata.cfg_mutex);
 	init_completion(&drvdata.send_cmd_complete);
 
 	/* Executing calls prior to returning from probe will lock the MCU. Schedule
-- 
2.55.0