[alsa-devel] [PATCH] add Steinberg UR44 USB Audio Interface support to quirks-table

[Cyrus Harmon]

On a somewhat related note, is there a way to apply changes to things 
in, say, sound/usb and compile/install those changes without a few 
kernel rebuild/install? Or, even better, without a reboot? Would 
certainly shorting the debug cycle time for me. In this case I'm 
interested in finding out what quirk->type is when it gets to 
snd_usb_create_quirk as it looks like the function in the quirk_funcs 
table that gets called here produces the first suspect error. Adding a 
dev_info, followed by a kernel rebuild, reinstall, reboot (and the fact 
that my broken nvidia drivers require reinstalling the video driver 
every time I install a new kernel) makes for a tedious process!

thanks!

Cyrus

On 11/05/2014 01:17 PM, Clemens Ladisch wrote:
> Cyrus Harmon wrote:
>> [    2.964094] snd-usb-audio 3-3.2:1.0: checking PCM interface
>> [    2.964104] snd-usb-audio: probe of 3-3.2:1.0 failed with error -5
>> [    2.966339] snd-usb-audio 3-3.2:1.1: checking PCM interface
>> [    2.966341] snd-usb-audio 3-3.2:1.1: altsets found
>> [    2.966342] snd-usb-audio 3-3.2:1.1: endpoint found
>> [    2.966343] snd-usb-audio 3-3.2:1.1: iso found
>> [    2.966344] snd-usb-audio 3-3.2:1.1: descriptors found
>> [    2.968544] usb 3-3.2:1.0: checking PCM interface
>> [    2.968546] usb 3-3.2:1.2: checking PCM interface
>> [    2.968547] usb 3-3.2:1.2: altsets found
>> [    2.968547] usb 3-3.2:1.2: endpoint found
>> [    2.968548] usb 3-3.2:1.2: iso found
>> [    2.968549] usb 3-3.2:1.2: descriptors found
>> [    2.970657] usb 3-3.2:1.3: checking PCM interface
>> [    2.970666] usb 3-3.2:1.4: checking PCM interface
>> [    2.970930] snd-usb-audio: probe of 3-3.2:1.1 failed with error -5
> Strange; in theory, this cannot happen.
>
> Please add this patch and try again.
>
>
> Regards,
> Clemens
>
>
> --- a/sound/usb/card.c
> +++ b/sound/usb/card.c
> @@ -536,7 +536,9 @@ snd_usb_audio_probe(struct usb_device *dev,
>   	err = 1; /* continue */
>   	if (quirk && quirk->ifnum != QUIRK_NO_INTERFACE) {
>   		/* need some special handlings */
> -		if ((err = snd_usb_create_quirk(chip, intf, &usb_audio_driver, quirk)) < 0)
> +		err = snd_usb_create_quirk(chip, intf, &usb_audio_driver, quirk);
> +		dev_info(&intf->dev, "quirk return code: %d\n", err);
> +		if (err < 0)
>   			goto __error;
>   	}
>
> @@ -547,11 +549,13 @@ snd_usb_audio_probe(struct usb_device *dev,
>   			goto __error;
>   		}
>   	}
> +	dev_info(&intf->dev, "probe step 2\n");
>
>   	/* we are allowed to call snd_card_register() many times */
>   	if (snd_card_register(chip->card) < 0) {
>   		goto __error;
>   	}
> +	dev_info(&intf->dev, "probe step 3\n");
>
>   	usb_chip[chip->index] = chip;
>   	chip->num_interfaces++;
> @@ -560,6 +564,7 @@ snd_usb_audio_probe(struct usb_device *dev,
>   	return chip;
>
>    __error:
> +	dev_info(&intf->dev, "probe failed\n");
>   	if (chip) {
>   		if (!chip->num_interfaces)
>   			snd_card_free(chip->card);
> --- a/sound/usb/quirks.c
> +++ b/sound/usb/quirks.c
> @@ -367,6 +367,7 @@ static int create_autodetect_quirks(struct snd_usb_audio *chip,
>   	err = create_autodetect_quirk(chip, iface, driver);
>   	if (err < 0)
>   		return err;
> +	dev_info(&iface->dev, "first interface successful\n");
>
>   	/*
>   	 * ALSA PCM playback/capture devices cannot be registered in two steps,
> @@ -385,9 +386,13 @@ static int create_autodetect_quirks(struct snd_usb_audio *chip,
>
>   		err = create_autodetect_quirk(chip, iface, driver);
>   		if (err >= 0)
> +		{
>   			usb_driver_claim_interface(driver, iface, (void *)-1L);
> +			dev_info(&iface->dev, "interface %d successful\n", ifnum);
> +		}
>   	}
>
> +	dev_info(&iface->dev, "create_autodetect_quirks successful\n");
>   	return 0;
>   }
>