diff options
| author | David Henningsson <david.henningsson@canonical.com> | 2013-05-08 15:33:11 +0200 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2013-05-08 15:43:56 +0200 |
| commit | d24f5a9ad9febffa53b1d3fcdf36c9a2283d848e (patch) | |
| tree | e5e0ecd75cfae2e45f964a05e55b9d7f874e39da | |
| parent | 17df3f55652f7ea8fb1197b5c32e227b3da9f215 (diff) | |
ALSA: Add comment for control TLV API
Userspace is not meant to have to handle all strange dB ranges,
so add a specification comment.
Signed-off-by: David Henningsson <david.henningsson@canonical.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
| -rw-r--r-- | include/sound/tlv.h | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/include/sound/tlv.h b/include/sound/tlv.h index 28c65e1ada21..e11e179420a1 100644 --- a/include/sound/tlv.h +++ b/include/sound/tlv.h @@ -74,7 +74,11 @@ #define DECLARE_TLV_DB_LINEAR(name, min_dB, max_dB) \ unsigned int name[] = { TLV_DB_LINEAR_ITEM(min_dB, max_dB) } -/* dB range container */ +/* dB range container: + * Items in dB range container must be ordered by their values and by their + * dB values. This implies that larger values must correspond with larger + * dB values (which is also required for all other mixer controls). + */ /* Each item is: <min> <max> <TLV> */ #define TLV_DB_RANGE_ITEM(...) \ TLV_ITEM(SNDRV_CTL_TLVT_DB_RANGE, __VA_ARGS__) |