Re: [PATCH v3 1/2] ALSA: usb-audio: Skip reading sample rate on M-Audio Venom

On Mon, 24 Aug 2026 16:02:10 +0200,
Federico Valentín Andrade wrote:
> 
> The M-Audio Venom (0763:2084) is an USB Audio Class 1 compliant
> synth with an integrated audio interface, it does not implement
> GET_CUR on SAMPLING_FREQ_CONTROL, hanging up if requested on
> endpoint 0.
> 
> The first class request issued by the driver after enumeration is
> a GET_CUR on endpoint 0x02, freezing the device's USB microcontroller.
> Timing out on every transfer afterwards with -ETIMEDOUT, such as
> SET_INTERFACE, so neither the mixer nor any streaming interface is set up.
> 
> Analyzing a USBPcap capture of the Windows driver I found it never
> requests the sampling frequency, as the synth exposes a single
> discrete of 44100Hz on both streaming interfaces, thus asking for it
> is unnecessary.
> 
> So I applied get_sample_rate to avoid this check, and
> disable_autosuspend because the synth doesn't come back from being
> suspended.
> 
> Signed-off-by: Federico Valentín Andrade <[email protected]>

Applied both patches now.  Thanks.


Takashi