diff options
| author | Alexandru Tachici <alexandru.tachici@analog.com> | 2020-02-21 14:06:55 +0200 |
|---|---|---|
| committer | Jonathan Cameron <Jonathan.Cameron@huawei.com> | 2020-03-08 17:28:51 +0000 |
| commit | 2ddc982a6c172c141183ac954d44f01bc4f2fe72 (patch) | |
| tree | f8b0879d2807b3b55bbbc7d6c34bd1973182dcd9 /include/linux/iio | |
| parent | 2303248b291f537f0414a644a53483c71023136f (diff) | |
iio: industrialio-core: Fix debugfs read
Currently iio_debugfs_read_reg calls debugfs_reg_access
every time it is ran. Reading the same hardware register
multiple times during the same reading of a debugfs file
can cause unintended effects.
For example for each: cat iio:device0/direct_reg_access
the file_operations.read function will be called at least
twice. First will return the full length of the string in
bytes and the second will return 0.
This patch makes iio_debugfs_read_reg to call debugfs_reg_access
only when the user's buffer position (*ppos) is 0. (meaning
it is the beginning of a new reading of the debugfs file).
Fixes: e553f182d55b ("staging: iio: core: Introduce debugfs support, add support for direct register access")
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Alexandru Tachici <alexandru.tachici@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Diffstat (limited to 'include/linux/iio')
| -rw-r--r-- | include/linux/iio/iio.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/include/linux/iio/iio.h b/include/linux/iio/iio.h index 862ce0019eba..eed58ed2f368 100644 --- a/include/linux/iio/iio.h +++ b/include/linux/iio/iio.h @@ -568,6 +568,8 @@ struct iio_dev { #if defined(CONFIG_DEBUG_FS) struct dentry *debugfs_dentry; unsigned cached_reg_addr; + char read_buf[20]; + unsigned int read_buf_len; #endif }; |