[alsa-devel] [PATCH]: sound/usb/mixer.c: Volume quirks compare empty string kctl->id.name.

[Takashi Iwai]

At Wed, 16 May 2012 10:03:42 +0200,
Christian Melki wrote:
> 
> Takashi,
> 
> I tried it on 3.3.2 on my embedded PPC machine (snd_usb_mixer_vol_tlv -> mixer_vol_tlv). Works fine for me.

Thanks, it was already queued for 3.5 kernel.


Takashi

> 
> Regards,
> Christian 
> 
> 
> > At Mon, 7 May 2012 09:51:29 +0200,
> > Christian Melki wrote:
> > > 
> > > > > Hi,
> > > > > 
> > > > > Sorry to mail you directly. But I have tried to mail 
> > several times 
> > > > > to the mailing list but I don't get through. Everything 
> > checks out 
> > > > > fine, no html etc, other mailing lists work fine, but 
> > not alsa devel.
> > > > > Anyway, could you please have a look at this?
> > > > 
> > > > Could you resend the patch but just add me, Clemens and 
> > Daniel to Cc, so that it reaches to main developers for 
> > usb-audio?  Even if we take your patch as is, it'd be needed 
> > to be applicable via git-am.
> > > > 
> > > > 
> > > > thanks,
> > > > 
> > > > Takashi
> > > 
> > > Hi.
> > > 
> > > I noticied that volume quirks in usb-audio did not get applied.
> > > This is because kctl->id.name gets built properly _after_ 
> > calling the quirk adjustments.
> > > My solution is a bit ugly, but check_mapped_dB needs the 
> > adjustment before getting called.
> > > I split the call over the switch. If someone feels like 
> > writing something cleaner, please feel free.
> > > This works for me atleast.
> > 
> > It's not ugly, but it'd be better to split the code to handle 
> > the name string, call get_min_max_*(), then the rest for FU.
> > 
> > Could you check whether the patch below works?
> > 
> > 
> > thanks,
> > 
> > Takashi
> > 
> > ---
> > From: Takashi Iwai <tiwai at suse.de>
> > Subject: [PATCH] ALSA: usb-audio - Call get_min_max_*() after 
> > determining the  name string
> > 
> > get_min_max_with_quirks() must be called after the control id 
> > name string is determined, but the current code changes the 
> > id name string after calling the function.
> > 
> > Reported-by: Christian Melki <christian.melki at ericsson.com>
> > Signed-off-by: Takashi Iwai <tiwai at suse.de>
> > ---
> >  sound/usb/mixer.c |   26 +++++++++++++-------------
> >  1 file changed, 13 insertions(+), 13 deletions(-)
> > 
> > diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c index 
> > 3d70245..4f40ba8 100644
> > --- a/sound/usb/mixer.c
> > +++ b/sound/usb/mixer.c
> > @@ -1141,9 +1141,6 @@ static void build_feature_ctl(struct 
> > mixer_build *state, void *raw_desc,
> >  		len = snd_usb_copy_string_desc(state, nameid,
> >  				kctl->id.name, sizeof(kctl->id.name));
> >  
> > -	/* get min/max values */
> > -	get_min_max_with_quirks(cval, 0, kctl);
> > -
> >  	switch (control) {
> >  	case UAC_FU_MUTE:
> >  	case UAC_FU_VOLUME:
> > @@ -1175,17 +1172,7 @@ static void build_feature_ctl(struct 
> > mixer_build *state, void *raw_desc,
> >  		}
> >  		append_ctl_name(kctl, control == UAC_FU_MUTE ?
> >  				" Switch" : " Volume");
> > -		if (control == UAC_FU_VOLUME) {
> > -			check_mapped_dB(map, cval);
> > -			if (cval->dBmin < cval->dBmax || 
> > !cval->initialized) {
> > -				kctl->tlv.c = snd_usb_mixer_vol_tlv;
> > -				kctl->vd[0].access |= 
> > -					SNDRV_CTL_ELEM_ACCESS_TLV_READ |
> > -					
> > SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
> > -			}
> > -		}
> >  		break;
> > -
> >  	default:
> >  		if (! len)
> >  			strlcpy(kctl->id.name, 
> > audio_feature_info[control-1].name,
> > @@ -1193,6 +1180,19 @@ static void build_feature_ctl(struct 
> > mixer_build *state, void *raw_desc,
> >  		break;
> >  	}
> >  
> > +	/* get min/max values */
> > +	get_min_max_with_quirks(cval, 0, kctl);
> > +
> > +	if (control == UAC_FU_VOLUME) {
> > +		check_mapped_dB(map, cval);
> > +		if (cval->dBmin < cval->dBmax || !cval->initialized) {
> > +			kctl->tlv.c = snd_usb_mixer_vol_tlv;
> > +			kctl->vd[0].access |=
> > +				SNDRV_CTL_ELEM_ACCESS_TLV_READ |
> > +				SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
> > +		}
> > +	}
> > +
> >  	range = (cval->max - cval->min) / cval->res;
> >  	/* Are there devices with volume range more than 255? I 
> > use a bit more
> >  	 * to be sure. 384 is a resolution magic number found 
> > on Logitech
> > --
> > 1.7.9.2
> > 
> >