2 files changed, 36 insertions, 24 deletions

diff --git a/drivers/hid/i2c-hid/i2c-hid-core.c b/drivers/hid/i2c-hid/i2c-hid-core.c
index 4804d71e5293..65c1f20ec420 100644
--- a/drivers/hid/i2c-hid/i2c-hid-core.c
+++ b/drivers/hid/i2c-hid/i2c-hid-core.c
@@ -615,6 +615,17 @@ static int i2c_hid_get_raw_report(struct hid_device *hid,
 	if (report_type == HID_OUTPUT_REPORT)
 		return -EINVAL;
 
+	/*
+	 * In case of unnumbered reports the response from the device will
+	 * not have the report ID that the upper layers expect, so we need
+	 * to stash it the buffer ourselves and adjust the data size.
+	 */
+	if (!report_number) {
+		buf[0] = 0;
+		buf++;
+		count--;
+	}
+
 	/* +2 bytes to include the size of the reply in the query buffer */
 	ask_count = min(count + 2, (size_t)ihid->bufsize);
 
@@ -636,6 +647,9 @@ static int i2c_hid_get_raw_report(struct hid_device *hid,
 	count = min(count, ret_count - 2);
 	memcpy(buf, ihid->rawbuf + 2, count);
 
+	if (!report_number)
+		count++;
+
 	return count;
 }
 
@@ -652,17 +666,19 @@ static int i2c_hid_output_raw_report(struct hid_device *hid, __u8 *buf,
 
 	mutex_lock(&ihid->reset_lock);
 
-	if (report_id) {
-		buf++;
-		count--;
-	}
-
+	/*
+	 * Note that both numbered and unnumbered reports passed here
+	 * are supposed to have report ID stored in the 1st byte of the
+	 * buffer, so we strip it off unconditionally before passing payload
+	 * to i2c_hid_set_or_send_report which takes care of encoding
+	 * everything properly.
+	 */
 	ret = i2c_hid_set_or_send_report(client,
 				report_type == HID_FEATURE_REPORT ? 0x03 : 0x02,
-				report_id, buf, count, use_data);
+				report_id, buf + 1, count - 1, use_data);
 
-	if (report_id && ret >= 0)
-		ret++; /* add report_id to the number of transfered bytes */
+	if (ret >= 0)
+		ret++; /* add report_id to the number of transferred bytes */
 
 	mutex_unlock(&ihid->reset_lock);
 
diff --git a/drivers/hid/i2c-hid/i2c-hid-of-goodix.c b/drivers/hid/i2c-hid/i2c-hid-of-goodix.c
index b4dad66fa954..ec6c73f75ffe 100644
--- a/drivers/hid/i2c-hid/i2c-hid-of-goodix.c
+++ b/drivers/hid/i2c-hid/i2c-hid-of-goodix.c
@@ -27,7 +27,6 @@ struct i2c_hid_of_goodix {
 
 	struct regulator *vdd;
 	struct notifier_block nb;
-	struct mutex regulator_mutex;
 	struct gpio_desc *reset_gpio;
 	const struct goodix_i2c_hid_timing_data *timings;
 };
@@ -67,8 +66,6 @@ static int ihid_goodix_vdd_notify(struct notifier_block *nb,
 		container_of(nb, struct i2c_hid_of_goodix, nb);
 	int ret = NOTIFY_OK;
 
-	mutex_lock(&ihid_goodix->regulator_mutex);
-
 	switch (event) {
 	case REGULATOR_EVENT_PRE_DISABLE:
 		gpiod_set_value_cansleep(ihid_goodix->reset_gpio, 1);
@@ -87,8 +84,6 @@ static int ihid_goodix_vdd_notify(struct notifier_block *nb,
 		break;
 	}
 
-	mutex_unlock(&ihid_goodix->regulator_mutex);
-
 	return ret;
 }
 
@@ -102,8 +97,6 @@ static int i2c_hid_of_goodix_probe(struct i2c_client *client,
 	if (!ihid_goodix)
 		return -ENOMEM;
 
-	mutex_init(&ihid_goodix->regulator_mutex);
-
 	ihid_goodix->ops.power_up = goodix_i2c_hid_power_up;
 	ihid_goodix->ops.power_down = goodix_i2c_hid_power_down;
 
@@ -130,25 +123,28 @@ static int i2c_hid_of_goodix_probe(struct i2c_client *client,
 	 *   long. Holding the controller in reset apparently draws extra
 	 *   power.
 	 */
-	mutex_lock(&ihid_goodix->regulator_mutex);
 	ihid_goodix->nb.notifier_call = ihid_goodix_vdd_notify;
 	ret = devm_regulator_register_notifier(ihid_goodix->vdd, &ihid_goodix->nb);
-	if (ret) {
-		mutex_unlock(&ihid_goodix->regulator_mutex);
+	if (ret)
 		return dev_err_probe(&client->dev, ret,
 			"regulator notifier request failed\n");
-	}
 
 	/*
 	 * If someone else is holding the regulator on (or the regulator is
 	 * an always-on one) we might never be told to deassert reset. Do it
-	 * now. Here we'll assume that someone else might have _just
-	 * barely_ turned the regulator on so we'll do the full
-	 * "post_power_delay" just in case.
+	 * now... and temporarily bump the regulator reference count just to
+	 * make sure it is impossible for this to race with our own notifier!
+	 * We also assume that someone else might have _just barely_ turned
+	 * the regulator on so we'll do the full "post_power_delay" just in
+	 * case.
 	 */
-	if (ihid_goodix->reset_gpio && regulator_is_enabled(ihid_goodix->vdd))
+	if (ihid_goodix->reset_gpio && regulator_is_enabled(ihid_goodix->vdd)) {
+		ret = regulator_enable(ihid_goodix->vdd);
+		if (ret)
+			return ret;
 		goodix_i2c_hid_deassert_reset(ihid_goodix, true);
-	mutex_unlock(&ihid_goodix->regulator_mutex);
+		regulator_disable(ihid_goodix->vdd);
+	}
 
 	return i2c_hid_core_probe(client, &ihid_goodix->ops, 0x0001, 0);
 }