25 May
2010
25 May
'10
11 p.m.
2010/5/25 Clemens Ladisch clemens@ladisch.de
Raymond Yau wrote:
I have doubt about DECLARE_TLV_DB_LINEAR(ak4396_db_scale,
TLV_DB_GAIN_MUTE, 0);
since the datasheet mention that dB range is only -48dB to 0dB
ATT = 20 log10 (ATT_DATA / 255) [dB]
How can AK4396 has scale of -inf DB to 0dB in the driver code ?
When ATT_DATA = 0, there is no output, which is an attenuation of -inf. The next value, ATT_DATA = 1, results in ATT = -48 dB.
But snd_mixer_selem_get_playback_dB_range() does not return 48dB **