[PATCH] hid: thingm: reorder calls in thingm_probe

[PATCH] hid: thingm: reorder calls in thingm_probe

[Heiner Kallweit]

Based on a suggestion from Benjamin move hid_hw_start() after
thingm_version() to avoid potential races.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
---
 drivers/hid/hid-thingm.c | 31 +++++++++++++------------------
 1 file changed, 13 insertions(+), 18 deletions(-)

diff --git a/drivers/hid/hid-thingm.c b/drivers/hid/hid-thingm.c
index f4196ac..847a497 100644
--- a/drivers/hid/hid-thingm.c
+++ b/drivers/hid/hid-thingm.c
@@ -216,17 +216,13 @@ static int thingm_probe(struct hid_device *hdev, const struct hid_device_id *id)
 
 	err = hid_parse(hdev);
 	if (err)
-		goto error;
-
-	err = hid_hw_start(hdev, HID_CONNECT_HIDRAW);
-	if (err)
-		goto error;
+		return err;
 
 	mutex_init(&tdev->lock);
 
 	err = thingm_version(tdev);
 	if (err)
-		goto stop;
+		return err;
 
 	hid_dbg(hdev, "firmware version: %c.%c\n",
 			tdev->version.major, tdev->version.minor);
@@ -237,17 +233,18 @@ static int thingm_probe(struct hid_device *hdev, const struct hid_device_id *id)
 
 	if (!tdev->fwinfo) {
 		hid_err(hdev, "unsupported firmware %c\n", tdev->version.major);
-		err = -ENODEV;
-		goto stop;
+		return -ENODEV;
 	}
 
 	tdev->rgb = devm_kzalloc(&hdev->dev,
 			sizeof(struct thingm_rgb) * tdev->fwinfo->numrgb,
 			GFP_KERNEL);
-	if (!tdev->rgb) {
-		err = -ENOMEM;
-		goto stop;
-	}
+	if (!tdev->rgb)
+		return -ENOMEM;
+
+	err = hid_hw_start(hdev, HID_CONNECT_HIDRAW);
+	if (err)
+		return err;
 
 	for (i = 0; i < tdev->fwinfo->numrgb; ++i) {
 		struct thingm_rgb *rgb = tdev->rgb + i;
@@ -255,15 +252,13 @@ static int thingm_probe(struct hid_device *hdev, const struct hid_device_id *id)
 		rgb->tdev = tdev;
 		rgb->num = tdev->fwinfo->first + i;
 		err = thingm_init_rgb(rgb);
-		if (err)
-			goto stop;
+		if (err) {
+			hid_hw_stop(hdev);
+			return err;
+		}
 	}
 
 	return 0;
-stop:
-	hid_hw_stop(hdev);
-error:
-	return err;
 }
 
 static const struct hid_device_id thingm_table[] = {
-- 
2.7.1

Re: [PATCH] hid: thingm: reorder calls in thingm_probe

[Jiri Kosina]

On Tue, 1 Mar 2016, Heiner Kallweit wrote:

> Based on a suggestion from Benjamin move hid_hw_start() after
> thingm_version() to avoid potential races.

Please make the changelog much more verbose. Namely please describe the 
exact problems this patch is fixing (IOW why we'd want this patch in the 
first place).

Thanks,

-- 
Jiri Kosina
SUSE Labs