iio: chemical: vz89x: prevent corrupted buffer from being read
Signed-off-by: Matt Ranostay <mranostay@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
diff --git a/drivers/iio/chemical/vz89x.c b/drivers/iio/chemical/vz89x.c
index 289d291..cd3870e 100644
--- a/drivers/iio/chemical/vz89x.c
+++ b/drivers/iio/chemical/vz89x.c
@@ -55,6 +55,7 @@
struct mutex lock;
int (*xfer)(struct vz89x_data *data, u8 cmd);
+ bool is_valid;
unsigned long last_update;
u8 buffer[VZ89TE_REG_MEASUREMENT_RD_SIZE];
};
@@ -229,7 +230,10 @@
/* sensor can only be polled once a second max per datasheet */
if (!time_after(jiffies, data->last_update + HZ))
- return 0;
+ return data->is_valid ? 0 : -EAGAIN;
+
+ data->is_valid = false;
+ data->last_update = jiffies;
ret = data->xfer(data, chip->cmd);
if (ret < 0)
@@ -239,7 +243,7 @@
if (ret)
return -EAGAIN;
- data->last_update = jiffies;
+ data->is_valid = true;
return 0;
}