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From:   Ruslan Bilovol <ruslan.bilovol@gmail.com>
Date:   Mon, 14 May 2018 12:36:14 +0300
Message-ID: <CAB=otbRx01uackLJtaOKCzT9tc5V9Nc62tV42Pie3rTd-exrKQ@mail.gmail.com>
Subject: Re: [PATCH v4 4/4] ALSA: usb-audio: UAC3: Parse Input Terminal number
 of channels.
To:     Jorge <jorge.sanjuan@codethink.co.uk>
Cc:     Takashi Iwai <tiwai@suse.com>, alsa-devel@alsa-project.org,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        linux-kernel@vger.kernel.org
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On Mon, May 14, 2018 at 11:54 AM, Jorge <jorge.sanjuan@codethink.co.uk> wrote:
>
>
> On 11/05/18 16:25, Jorge Sanjuan wrote:
>>
>> Obtain the number of channels for the Input Terminal from the
>> Logical Cluster Descriptor. This achieves a useful minimal parsing
>> of this unit so it can be used in other units in the topology.
>>
>> Signed-off-by: Jorge Sanjuan <jorge.sanjuan@codethink.co.uk>
>> ---
>>   sound/usb/mixer.c | 4 ++--
>>   1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c
>> index 431f3c319839..19b25fbc7437 100644
>> --- a/sound/usb/mixer.c
>> +++ b/sound/usb/mixer.c
>> @@ -903,9 +903,9 @@ static int check_input_term(struct mixer_build *state,
>> int id,
>>                                  * recursion calls */
>>                                 term->id = id;
>>                                 term->type =
>> le16_to_cpu(d->wTerminalType);
>> +                               term->channels =
>> get_cluster_channels_v3(state, d->wClusterDescrID);
>
>
>
> Sorry about this. I just spotted that I should have used the helper function
> I added to access d->wClusterDescrID `uac3_mixer_unit_wClusterDescrID`.
>
> I got the sparse warning for the endianess and realized that. I'll resend
> this one patch.

While here, please add checking output of get_cluster_channels_v3() as
it can return negative errno.

BTW, I've just tested your Mixer patches and this is the only comment I have
so far.

Thanks,
Ruslan

>
>>   -                             /* REVISIT: UAC3 IT doesn't have
>> channels/cfg */
>> -                               term->channels = 0;
>> +                               /* REVISIT: UAC3 IT doesn't have channels
>> cfg */
>>                                 term->chconfig = 0;
>>                                 term->name =
>> le16_to_cpu(d->wTerminalDescrStr);
>>
>