Re: [PATCH] ALSA: usb-audio: endpoint : remove redundant check before usb_free_coherent()

[Takashi Iwai <tiwai@xxxxxxx>]

On Thu, 04 Feb 2021 03:05:18 +0100,
Xu Wang wrote:
> 
> usb_free_coherent() is safe with NULL addr and this check is
> not required.

The check there isn't about NULL buffer or not; instead it checks
whether the buffer was allocated for each or it shares the single
buffer (for sync endpoints).  In the latter case, your patch will lead
to double-free.


thanks,

Takashi