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Date:   Fri, 21 Apr 2023 17:11:59 +0200
Message-ID: <87mt31qngg.wl-tiwai@suse.de>
From:   Takashi Iwai <tiwai@suse.de>
To:     Chris Down <chris@chrisdown.name>
Cc:     linux-kernel@vger.kernel.org, alsa-devel@alsa-project.org,
        Jaroslav Kysela <perex@perex.cz>, Takashi Iwai <tiwai@suse.com>
Subject: Re: [PATCH] usb-audio: Rate limit usb_set_interface error reporting
In-Reply-To: <ZEKiO7lh94QUyuAs@chrisdown.name>
References: <ZEKf8UYBYa1h4JWR@chrisdown.name>
        <87wn25qosu.wl-tiwai@suse.de>
        <ZEKiO7lh94QUyuAs@chrisdown.name>
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On Fri, 21 Apr 2023 16:48:27 +0200,
Chris Down wrote:
> 
> Hi Takashi,
> 
> Takashi Iwai writes:
> > This patch itself is safe and good to have, so I'm going to take it as
> > is.
> 
> Thanks!
> 
> > But I'm still curious in which code path the problem happens.  That
> > is, we should address such unnecessary repeats if possible.  Do you
> > have some more data?
> 
> Unfortunately not, I've been running with a kernel testing some other
> mm changes recently so haven't had a chance to debug what's going on
> here. But it starts like this:
> 
>     [Fri Apr 21 13:21:10 2023] usb 3-7: USB disconnect, device number 39
>     [Fri Apr 21 13:21:10 2023] usb 3-7.1: USB disconnect, device number 40
>     [Fri Apr 21 13:21:10 2023] usb 3-7.1.1: USB disconnect, device number 42
>     [Fri Apr 21 13:21:10 2023] usb 3-7.4: cannot submit urb (err = -19)
>     [Fri Apr 21 13:21:10 2023] usb 3-7.4: Unable to submit urb #2: -19 at snd_usb_queue_pending_output_urbs
>     [Fri Apr 21 13:21:10 2023] usb 3-7.4: cannot submit urb 0, error -19: no device
>     [Fri Apr 21 13:21:10 2023] usb 3-7.4: cannot submit urb 0, error -19: no device
>     [Fri Apr 21 13:21:10 2023] usb 3-7.4: cannot submit urb 0, error -19: no device
>     [Fri Apr 21 13:21:10 2023] usb 3-7.4: 1:0: usb_set_interface failed (-19)
>     [Fri Apr 21 13:21:10 2023] usb 3-7.4: 2:0: usb_set_interface failed (-19)
>     [Fri Apr 21 13:21:10 2023] usb 3-7.1.2: USB disconnect, device number 44
>     [Fri Apr 21 13:21:10 2023] usb 3-7.1.4: 1:1: usb_set_interface failed (-19)
>     [Fri Apr 21 13:21:10 2023] usb 3-7.1.4: 1:1: usb_set_interface failed (-19)
>     [Fri Apr 21 13:21:10 2023] usb 3-7.1.4: 1:1: usb_set_interface failed (-19)
>     [Fri Apr 21 13:21:10 2023] usb 3-7.1.4: 1:1: usb_set_interface failed (-19)
>     [Fri Apr 21 13:21:10 2023] usb 3-7.1.4: 1:1: usb_set_interface failed (-19)
>     [Fri Apr 21 13:21:10 2023] usb 3-7.1.4: 1:1: usb_set_interface failed (-19)
>     [Fri Apr 21 13:21:10 2023] usb 3-7.1.4: 1:1: usb_set_interface failed (-19)
>     [Fri Apr 21 13:21:10 2023] usb 3-7.1.4: 1:1: usb_set_interface failed (-19)
>     [... thousands of messages ensue ...]
> 
> So it looks like maybe some ordering is not quite right in
> destruction, perhaps only on multi-level USB topologies?

Hrm, is "usb 3-7.1.4" really the USB audio device?  The previous
errors like "Unable to submit urb #2..." are certainly for USB audio,
and those are with "usb 3-7.4".

You patch may still make sense, though.  So I'll keep it applied.


thanks,

Takashi