>-----Original Message----- >From: Takashi Iwai [mailto:tiwai@xxxxxxx] >Sent: Tuesday, July 07, 2009 12:56 PM >To: Harsha, Priya >Cc: Koul, Vinod; alsa-devel@xxxxxxxxxxxxxxxx >Subject: Re: [PATCH] [RFC 8/13] Intel SST sound card driver > >At Tue, 7 Jul 2009 12:46:38 +0530, >Harsha, Priya wrote: >> >> >> >> > >> >> >> >> + .access = SNDRV_CTL_ELEM_ACCESS_READWRITE, >> >> >> >> + .info = snd_intelmad_line_volume_info, >> >> >> >> + .get = snd_intelmad_volume_get, >> >> >> >> + .put = snd_intelmad_volume_set, >> >> >> > >> >> >> >Can it have the dB information via TLV? >> >> >> No. It actually differs across the 3 sound cards supported and it's >> >> >> not a direct TLV that can be used. >> >> > >> >> >Then you'd set a static TLV entry after creating the ctl element >> >> >instance, or return a TLV entry dynamically via the tlv callback. >> >> Sorry I misunderstood. The value that is passed in min and max is in >> >> dB. >> >> For min and max values, it's a static dB value that I return. But >> >> when the volume adjustments need to be done, based on the value >> >> given by ALSA, I set the sound card registers to reflect that dB >> >> value. >> > >> >The value to be set is always raw. That is, alsa-lib computes the >> >raw value from the given dB value based on the TLV information (dB >> >min/max), supposing the volume scale is logarithmic. >> > >> >Isn't it the case for you? >> Yes. I set the raw min and max values in db. And alsa-lib computes >> the volume value to be set (which is in between the min and max) and >> provides the same to the driver. The driver sets the corresponding >> sound card registers to reflect the same. In our case, the scale is >> not logarithmic in couple of sound cards and the vendor abstraction >> file would need to take care of the same to set the registers >> correctly. > >Then it can't be exported as the existing TLV. The currently defined >TLV types are logarithmic, linear, and combinations. >I think it's better to fix the driver side to be logarithmic. Ok. I will work on it. Thanks, Harsha _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
