[PATCH 3/3] hid: thingm: improve locking

[Heiner Kallweit <hkallweit1@gmail.com>]

When reading from the device the full operation including sending the
read command and the actual read should be protected by the mutex.
Facilitate this by changing the semantics of thingm_recv to include
sending the read command.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
---
 drivers/hid/hid-thingm.c | 28 +++++++++++++++++-----------
 1 file changed, 17 insertions(+), 11 deletions(-)

diff --git a/drivers/hid/hid-thingm.c b/drivers/hid/hid-thingm.c
index 5e35ec1..0e4b50c 100644
--- a/drivers/hid/hid-thingm.c
+++ b/drivers/hid/hid-thingm.c
@@ -77,9 +77,13 @@ static int thingm_send(struct thingm_device *tdev, u8 buf[REPORT_SIZE])
 			buf[0], buf[1], buf[2], buf[3], buf[4],
 			buf[5], buf[6], buf[7], buf[8]);
 
+	mutex_lock(&tdev->lock);
+
 	ret = hid_hw_raw_request(tdev->hdev, buf[0], buf, REPORT_SIZE,
 			HID_FEATURE_REPORT, HID_REQ_SET_REPORT);
 
+	mutex_unlock(&tdev->lock);
+
 	return ret < 0 ? ret : 0;
 }
 
@@ -87,16 +91,26 @@ static int thingm_recv(struct thingm_device *tdev, u8 buf[REPORT_SIZE])
 {
 	int ret;
 
+	mutex_lock(&tdev->lock);
+
+	ret = hid_hw_raw_request(tdev->hdev, buf[0], buf, REPORT_SIZE,
+			HID_FEATURE_REPORT, HID_REQ_SET_REPORT);
+	if (ret < 0)
+		goto err;
+
 	ret = hid_hw_raw_request(tdev->hdev, buf[0], buf, REPORT_SIZE,
 			HID_FEATURE_REPORT, HID_REQ_GET_REPORT);
 	if (ret < 0)
-		return ret;
+		goto err;
+
+	ret = 0;
 
 	hid_dbg(tdev->hdev, "<- %d %c %02hhx %02hhx %02hhx %02hhx %02hhx %02hhx %02hhx\n",
 			buf[0], buf[1], buf[2], buf[3], buf[4],
 			buf[5], buf[6], buf[7], buf[8]);
-
-	return 0;
+err:
+	mutex_unlock(&tdev->lock);
+	return ret;
 }
 
 static int thingm_version(struct thingm_device *tdev)
@@ -104,10 +118,6 @@ static int thingm_version(struct thingm_device *tdev)
 	u8 buf[REPORT_SIZE] = { REPORT_ID, 'v', 0, 0, 0, 0, 0, 0, 0 };
 	int err;
 
-	err = thingm_send(tdev, buf);
-	if (err)
-		return err;
-
 	err = thingm_recv(tdev, buf);
 	if (err)
 		return err;
@@ -135,14 +145,10 @@ static int thingm_led_set(struct led_classdev *ldev,
 	struct thingm_led *led = container_of(ldev, struct thingm_led, ldev);
 	int ret;
 
-	mutex_lock(&led->rgb->tdev->lock);
-
 	ret = thingm_write_color(led->rgb);
 	if (ret)
 		hid_err(led->rgb->tdev->hdev, "failed to write color\n");
 
-	mutex_unlock(&led->rgb->tdev->lock);
-
 	return ret;
 }
 
-- 
2.7.1