diff options
| -rw-r--r-- | drivers/iio/chemical/mhz19b.c | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/drivers/iio/chemical/mhz19b.c b/drivers/iio/chemical/mhz19b.c index 3c64154918b1..9d4cf432919e 100644 --- a/drivers/iio/chemical/mhz19b.c +++ b/drivers/iio/chemical/mhz19b.c @@ -52,6 +52,8 @@ struct mhz19b_state { struct completion buf_ready; u8 buf_idx; + bool buf_overflow; + /* * Serdev receive buffer. * When data is received from the MH-Z19B, @@ -106,6 +108,10 @@ static int mhz19b_serdev_cmd(struct iio_dev *indio_dev, int cmd, u16 arg) cmd_buf[8] = mhz19b_get_checksum(cmd_buf); /* Write buf to uart ctrl synchronously */ + st->buf_idx = 0; + st->buf_overflow = false; + reinit_completion(&st->buf_ready); + ret = serdev_device_write(serdev, cmd_buf, MHZ19B_CMD_SIZE, 0); if (ret < 0) return ret; @@ -121,6 +127,9 @@ static int mhz19b_serdev_cmd(struct iio_dev *indio_dev, int cmd, u16 arg) if (!ret) return -ETIMEDOUT; + if (st->buf_overflow) + return -EMSGSIZE; + if (st->buf[8] != mhz19b_get_checksum(st->buf)) { dev_err(dev, "checksum err"); return -EINVAL; @@ -240,6 +249,14 @@ static size_t mhz19b_receive_buf(struct serdev_device *serdev, { struct iio_dev *indio_dev = dev_get_drvdata(&serdev->dev); struct mhz19b_state *st = iio_priv(indio_dev); + size_t remaining = MHZ19B_CMD_SIZE - st->buf_idx; + + if (len > remaining) { + st->buf_idx = 0; + st->buf_overflow = true; + complete(&st->buf_ready); + return len; + } memcpy(st->buf + st->buf_idx, data, len); st->buf_idx += len; |