On Fri, Dec 24, 2021 at 11:13:49AM +0700, Quan Nguyen wrote:

+static int read_i2c_block_data(struct i2c_client *client, u16 address, u16 length, u8 *data)
+{
+	unsigned char outbuf[MAX_READ_BLOCK_LENGTH];
+	unsigned char inbuf[2];
+	struct i2c_msg msgs[2];
+	ssize_t ret;
+
+	inbuf[0] = (address & 0xff);
+	inbuf[1] = length;
+
+	msgs[0].addr = client->addr;
+	msgs[0].flags = client->flags & I2C_M_TEN;
+	msgs[0].len = 2;
+	msgs[0].buf = inbuf;
+
+	msgs[1].addr = client->addr;
+	msgs[1].flags = (client->flags  & I2C_M_TEN) | I2C_M_RD;
+	msgs[1].len = length;
+	msgs[1].buf = outbuf;
+
+	ret = i2c_transfer(client->adapter, msgs, NUM_I2C_MESSAGES);
+	if (ret < 0)

regmap already supports bulk data access so it's not clear why we
would open code this.  Given that this is a single I2C transfer
it's also unclear why we'd need to export the regmap lock - a
single I2C transfer is atomic at the bus level so the regmap lock
isn't providing any additional concurrency protection.