[alsa-devel] [PATCH] Mixer quirk for QuickCam E 3500

Takashi Iwai tiwai at suse.de
Wed Jul 22 00:01:46 CEST 2009


At Tue, 21 Jul 2009 23:57:46 +0200,
Alexey Fisher wrote:
> 
> Takashi Iwai schrieb:
> > At Tue, 21 Jul 2009 23:10:42 +0200,
> > Alexey Fisher wrote:
> >> 1. E3500 report cval->max more than it actually can handel, so if you
> >> set 95% capture level it will be muted.
> >> 2. betwen cval->min and cval-max(real) is 2940 control units,
> >> but real are only 7.
> >> 3. we found only 7 real control units, with cval->res = 384,
> >> but alsa can't handel less than 10 controls, so make it more
> >> and set cval->res = 192.
> >>
> >> Signed-off-by: Alexey Fisher <bug-track at fisher-privat.net>
> > 
> > Thanks for the patch.  The added code looks almost good.
> > But, it's better to put your code into another place, e.g. a bit
> > later so that you don't insert it between the comment and the other
> > code.  Also, if you use switch(), you need break.
> > 
> > In your case, simply put a new if () block with a proper comment
> > after that switch() block.  It's not necessarily merged into a single
> > switch.  The compiler should be clever enough.
> > 
> > Also, try to keep the patch checkpatch.pl-clean.  Run it once before
> > submitting your patch.
> > 
> > Could you fix these and repost?
> > 
> > 
> > thanks,
> > 
> > Takashi
> > 
> >> ---
> >>  sound/usb/usbmixer.c |    7 +++++++
> >>  1 files changed, 7 insertions(+), 0 deletions(-)
> >>
> >> diff --git a/sound/usb/usbmixer.c b/sound/usb/usbmixer.c
> >> index 4bd3a7a..72562ee 100644
> >> --- a/sound/usb/usbmixer.c
> >> +++ b/sound/usb/usbmixer.c
> >> @@ -995,6 +995,13 @@ static void build_feature_ctl(struct mixer_build *state, unsigned char *desc,
> >>  	/* is not very clear from datasheets */
> >>  	/* I hope that the min value is -15360 for newer firmware --jk */
> >>  	switch (state->chip->usb_id) {
> >> +	case USB_ID(0x046d, 0x09a4):
> >> +		if (!strcmp(kctl->id.name, "Mic Capture Volume")) {
> >> +			snd_printk(KERN_INFO "using volume control quirk for the QuickCam E3500\n");
> >> +			cval->min = 6080;
> >> +			cval->max = 8768;
> >> +			cval->res = 192;
> >> +		}
> >>  	case USB_ID(0x0471, 0x0101):
> >>  	case USB_ID(0x0471, 0x0104):
> >>  	case USB_ID(0x0471, 0x0105):
> 
> There is some thing wrong with this. After suspend and resume this quirk 
> not working. Even replug the cam not help, only reloading of 
> snd_usb_sound will do it work again.

But isn't it irrelevant with your patch?


Takashi


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