[alsa-devel] USB Audio Interface / Denon MC7000 and MC8000 controller

Alexander Tsoy alexander at tsoy.me
Fri Feb 7 18:45:05 CET 2020


В Пт, 07/02/2020 в 15:39 +0100, Tobias пишет:
> Thank you very much again for your quick input.
> Unfortunately the new patch caused a compilation error so I tried to 
> compile the module where the kernel stopped at first place which
> gave 
> following message.
> 
> 
> $ sudo make modules
> 
>    CALL    scripts/checksyscalls.sh
>    CALL    scripts/atomic/check-atomics.sh
>    DESCEND  objtool
>    CC [M]  sound/usb/clock.o
> In file included from ./include/linux/usb/ch9.h:36:0,
>                   from ./include/linux/usb.h:6,
>                   from sound/usb/clock.c:9:
> sound/usb/clock.c: In function ‘set_sample_rate_v2v3’:
> sound/usb/clock.c:610:10: error: ‘entity_id’ undeclared (first use
> in 
> this function)
>            entity_id);
>            ^
> ./include/linux/device.h:1774:32: note: in definition of macro
> ‘dev_err’
>    _dev_err(dev, dev_fmt(fmt), ##__VA_ARGS__)
>                                  ^
> sound/usb/clock.c:608:3: note: in expansion of macro ‘usb_audio_err’
>     usb_audio_err(chip,
>     ^
> sound/usb/clock.c:610:10: note: each undeclared identifier is
> reported 
> only once for each function it appears in
>            entity_id);
>            ^
> ./include/linux/device.h:1774:32: note: in definition of macro
> ‘dev_err’
>    _dev_err(dev, dev_fmt(fmt), ##__VA_ARGS__)
>                                  ^
> sound/usb/clock.c:608:3: note: in expansion of macro ‘usb_audio_err’
>     usb_audio_err(chip,
>     ^
> scripts/Makefile.build:265: die Regel für Ziel „sound/usb/clock.o“ 
> scheiterte
> make[2]: *** [sound/usb/clock.o] Fehler 1
> scripts/Makefile.build:503: die Regel für Ziel „sound/usb“ scheiterte
> make[1]: *** [sound/usb] Fehler 2
> Makefile:1693: die Regel für Ziel „sound“ scheiterte
> make: *** [sound] Fehler 2
> 
> 
> Hope that helps to determine what went wrong. If you need anything
> else, 
> then please let me know.

Sorry, this was a copy-paste error, the argument should be "clock", not
"entity_id".

Please try the patch below. It should just print

... uac_clock_source_is_valid(): err: X ; data: X

to the kernel log. Hopefully this is a final peace of data I need.


diff --git a/sound/usb/clock.c b/sound/usb/clock.c
index 018b1ecb5404..65ee5c24c5d1 100644
--- a/sound/usb/clock.c
+++ b/sound/usb/clock.c
@@ -187,6 +187,8 @@ static bool uac_clock_source_is_valid(struct snd_usb_audio *chip,
                  snd_usb_ctrl_intf(chip) | (source_id << 8),
                  &data, sizeof(data));
 
+   dev_info(&dev->dev, "%s(): err: %d ; data: %d\n", __func__, err, data);
+
    if (err < 0) {
        dev_warn(&dev->dev,
             "%s(): cannot get clock validity for id %d\n",

> 
> Cheers
> Tobias
> 
> 
> Am 07.02.20 um 09:15 schrieb Takashi Iwai:
> > On Thu, 06 Feb 2020 23:09:33 +0100,
> > Alexander Tsoy wrote:
> > > В Чт, 06/02/2020 в 11:06 +0100, Tobias пишет:
> > > > Thank you so much Alexander!
> > > > I used latest Kernel and patched as you suggested. The Device
> > > > is
> > > > working
> > > > now giving sound on all 4 channels, even though dmesg still
> > > > shows
> > > > the
> > > > error message as you can see here:
> > > > 
> > > > uname -a:
> > > > Linux tobias-V130 5.5.2 #1 SMP Thu Feb 6 09:41:57 CET 2020
> > > > x86_64
> > > > x86_64
> > > > x86_64 GNU/Linux
> > > > 
> > > > dmesg:
> > > > [   62.918777] usb 1-1.3: new high-speed USB device number 6
> > > > using
> > > > xhci_hcd
> > > > [   62.939293] usb 1-1.3: New USB device found, idVendor=15e4,
> > > > idProduct=8004, bcdDevice=11.10
> > > > [   62.939295] usb 1-1.3: New USB device strings: Mfr=1,
> > > > Product=2,
> > > > SerialNumber=3
> > > > [   62.939297] usb 1-1.3: Product: DENON DJ MC7000
> > > > [   62.939298] usb 1-1.3: Manufacturer: DENON DJ
> > > > [   62.939299] usb 1-1.3: SerialNumber: 201603
> > > > [   62.942232] usb 1-1.3: clock source 65 is not valid, cannot
> > > > use
> > > > [   62.943998] usb 1-1.3: clock source 65 is not valid, cannot
> > > > use
> > > > [   63.013306] usb 1-1.3: clock source 65 is not valid, cannot
> > > > use
> > > > [   63.028912] usb 1-1.3: clock source 65 is not valid, cannot
> > > > use
> > > > [   63.029675] usb 1-1.3: clock source 65 is not valid, cannot
> > > > use
> > > > [   63.037813] usb 1-1.3: clock source 65 is not valid, cannot
> > > > use
> > > > [   63.063865] usb 1-1.3: clock source 65 is not valid, cannot
> > > > use
> > > Yes, this is expected.
> > > 
> > > > I checked in file /sound/usb/clock.c that within functions
> > > > 
> > > > static int __uac_clock_find_source
> > > > static int __uac3_clock_find_source
> > > > 
> > > > there is another check that possibly gives the warning.
> > > > 
> > > > Maybe the warning "cannot use" should not be displayed when a
> > > > Denon
> > > > Audio device is attached as it is misleading.
> > > Please try the patch below. I've dropped UAC3 support and changed
> > > __uac_clock_find_source() and __uac3_clock_find_source() to print
> > > errors only in debug mode, as we make the final decision about
> > > clock
> > > validity in set_sample_rate_v2v3().
> > > 
> > > 
> > > Dear Takashi, what do you think about this approach. Is it
> > > acceptable?
> > Yes, the approach looks good to me.
> > Just a few comments:
> > 
> > > diff --git a/sound/usb/clock.c b/sound/usb/clock.c
> > > index 018b1ecb5404..e978b46efc85 100644
> > > --- a/sound/usb/clock.c
> > > +++ b/sound/usb/clock.c
> > > @@ -197,6 +197,32 @@ static bool uac_clock_source_is_valid(struct
> > > snd_usb_audio *chip,
> > >   	return data ? true :  false;
> > >   }
> > >   
> > > +/*
> > > + * Assume the clock is valid if clock source supports only one
> > > single sample
> > > + * rate, its type is not external and a terminal is connected
> > > directly to it
> > > + * (there is no clock selector). This is needed for some Denon
> > > DJ controllers,
> > > + * that always reports that clock is invalid.
> > > + */
> > > +static bool uac_clock_source_is_valid_quirk(struct snd_usb_audio
> > > *chip,
> > > +					    struct audioformat *fmt,
> > > +					    int clock)
> > > +{
> > > +	if (fmt->protocol == UAC_VERSION_2) {
> > > +		struct uac_clock_source_descriptor *cs_desc =
> > > +			snd_usb_find_clock_source(chip->ctrl_intf,
> > > clock);
> > > +
> > > +		if (!cs_desc)
> > > +			return false;
> > > +
> > > +		return (fmt->nr_rates == 1 &&
> > > +			(fmt->clock & 0xff) == cs_desc->bClockID &&
> > > +			(cs_desc->bmAttributes & 0x3) !=
> > > +				UAC_CLOCK_SOURCE_TYPE_EXT);
> > > +	}
> > > +
> > > +	return false;
> > IMO it's safer to call from the specific failure path, i.e.
> > 
> >   static bool uac_clock_source_is_valid(....)
> >   {
> > 	....
> > 	err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0),
> > UAC2_CS_CUR,
> > 			      USB_TYPE_CLASS | USB_RECIP_INTERFACE |
> > USB_DIR_IN,
> > 			      UAC2_CS_CONTROL_CLOCK_VALID << 8,
> > 			      snd_usb_ctrl_intf(chip) | (source_id <<
> > 8),
> > 			      &data, sizeof(data));
> > 
> > 	if (err < 0) {
> > 
> > 		if (uac_clock_source_is_valid_quirk(....))
> > 			return true;
> > 
> > 		dev_warn(&dev->dev,
> > 			 "%s(): cannot get clock validity for id %d\n",
> > 			   __func__, source_id);
> > 		return false;
> > 	}
> > 
> > Then you can pass cs_desc there, too.
> > 
> > 
> > > +}
> > > +
> > >   static int __uac_clock_find_source(struct snd_usb_audio *chip,
> > > int entity_id,
> > >   				   unsigned long *visited, bool
> > > validate)
> > >   {
> > > @@ -219,7 +245,7 @@ static int __uac_clock_find_source(struct
> > > snd_usb_audio *chip, int entity_id,
> > >   		entity_id = source->bClockID;
> > >   		if (validate &&
> > > !uac_clock_source_is_valid(chip, UAC_VERSION_2,
> > >   								
> > > entity_id)) {
> > > -			usb_audio_err(chip,
> > > +			usb_audio_dbg(chip,
> > >   				"clock source %d is not valid,
> > > cannot use\n",
> > >   				entity_id);
> > >   			return -ENXIO;
> > Hm, it's not good to hide the error message always.  This is a
> > common
> > error on many devices and suppressing it would look cleaner but
> > also
> > hide what's the reason.  Maybe we can add nowarn bool flag for
> > certain
> > code paths?
> > 
> > 
> > thanks,
> > 
> > Takashi



More information about the Alsa-devel mailing list