Re: [PATCH] ALSA: usb-audio: Check presence of valid altsetting control

[Takashi Iwai <tiwai@xxxxxxx>]

On Mon, 29 Jan 2024 13:12:54 +0100,
Alexander Tsoy wrote:
> 
> Many devices with a single alternate setting do not have a Valid
> Alternate Setting Control and validation performed by
> validate_sample_rate_table_v2v3() doesn't work on them and is not
> really needed. So check the presense of control before sending
> altsetting validation requests.
> 
> MOTU Microbook IIc is suffering the most without this check. It
> takes up to 40 seconds to bootup due to how slow it switches
> sampling rates:
> 
> [ 2659.164824] usb 3-2: New USB device found, idVendor=07fd, idProduct=0004, bcdDevice= 0.60
> [ 2659.164827] usb 3-2: New USB device strings: Mfr=1, Product=2, SerialNumber=0
> [ 2659.164829] usb 3-2: Product: MicroBook IIc
> [ 2659.164830] usb 3-2: Manufacturer: MOTU
> [ 2659.166204] usb 3-2: Found last interface = 3
> [ 2679.322298] usb 3-2: No valid sample rate available for 1:1, assuming a firmware bug
> [ 2679.322306] usb 3-2: 1:1: add audio endpoint 0x3
> [ 2679.322321] usb 3-2: Creating new data endpoint #3
> [ 2679.322552] usb 3-2: 1:1 Set sample rate 96000, clock 1
> [ 2684.362250] usb 3-2: 2:1: cannot get freq (v2/v3): err -110
> [ 2694.444700] usb 3-2: No valid sample rate available for 2:1, assuming a firmware bug
> [ 2694.444707] usb 3-2: 2:1: add audio endpoint 0x84
> [ 2694.444721] usb 3-2: Creating new data endpoint #84
> [ 2699.482103] usb 3-2: 2:1 Set sample rate 96000, clock 1
> 
> Signed-off-by: Alexander Tsoy <alexander@xxxxxxx>

Thanks, applied now.

But at the next time, please put maintainers to Cc, so that it can be
caught better.


Takashi