When an error occurs during USB disconnection sometimes things can go
wrong as endpoint_set_interface may end up being called repeatedly. For
example:
% dmesg --notime | grep 'usb 3-7.1.4' | sort | uniq -c | head -2
3069 usb 3-7.1.4: 1:1: usb_set_interface failed (-19)
908 usb 3-7.1.4: 1:1: usb_set_interface failed (-71)
In my case, there sometimes are hundreds of these usb_set_interface
failure messages a second when I disconnect the hub that has my USB
audio device.
These messages can take a huge amount of the kmsg ringbuffer and don't
provide any extra information over the previous ones, so ratelimit them.
Signed-off-by: Chris Down <[email protected]>
---
sound/usb/endpoint.c | 5 +++--
sound/usb/usbaudio.h | 2 ++
2 files changed, 5 insertions(+), 2 deletions(-)
diff --git a/sound/usb/endpoint.c b/sound/usb/endpoint.c
index 647fa054d8b1..2cd99cc8c360 100644
--- a/sound/usb/endpoint.c
+++ b/sound/usb/endpoint.c
@@ -916,8 +916,9 @@ static int endpoint_set_interface(struct snd_usb_audio *chip,
ep->iface, altset, ep->ep_num);
err = usb_set_interface(chip->dev, ep->iface, altset);
if (err < 0) {
- usb_audio_err(chip, "%d:%d: usb_set_interface failed (%d)\n",
- ep->iface, altset, err);
+ usb_audio_err_ratelimited(
+ chip, "%d:%d: usb_set_interface failed (%d)\n",
+ ep->iface, altset, err);
return err;
}
diff --git a/sound/usb/usbaudio.h b/sound/usb/usbaudio.h
index f5a8dca66457..38a85b2c9a73 100644
--- a/sound/usb/usbaudio.h
+++ b/sound/usb/usbaudio.h
@@ -67,6 +67,8 @@ struct snd_usb_audio {
#define usb_audio_err(chip, fmt, args...) \
dev_err(&(chip)->dev->dev, fmt, ##args)
+#define usb_audio_err_ratelimited(chip, fmt, args...) \
+ dev_err_ratelimited(&(chip)->dev->dev, fmt, ##args)
#define usb_audio_warn(chip, fmt, args...) \
dev_warn(&(chip)->dev->dev, fmt, ##args)
#define usb_audio_info(chip, fmt, args...) \
--
2.40.0
Takashi Iwai writes:
>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".
There are two USB audio devices -- 3-7.1.4 is input, 3-7.4 is output.
% dmesg --notime | grep -e 'usb 3-7.4' -e 'usb 3-7.1.4' | grep Product: | sort | uniq
usb 3-7.1.4: Product: USB2.0 Microphone
usb 3-7.4: Product: USB Audio Device
Thanks,
Chris
On Fri, 21 Apr 2023 17:16:59 +0200,
Chris Down wrote:
>
> Takashi Iwai writes:
> > 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".
>
> There are two USB audio devices -- 3-7.1.4 is input, 3-7.4 is output.
>
> % dmesg --notime | grep -e 'usb 3-7.4' -e 'usb 3-7.1.4' | grep Product: | sort | uniq
> usb 3-7.1.4: Product: USB2.0 Microphone
> usb 3-7.4: Product: USB Audio Device
Ah I see. Then those are two different sound cards?
The repeated call of usb_set_interface() might be avoided by the
additional check like below. But it's still puzzling how it happens,
because the only caller of endpoint_set_interface() you modified is
snd_usb_endpoint_prepare(), and it's called only from
snd_usb_pcm_prepare(). And, snd_usb_pcm_preapre() has the
snd_usb_lock_shutdown() call, which does the check of the
card->shutdown flag that should be set by the USB disconnection
callback...
thanks,
Takashi
-- 8< --
--- a/sound/usb/endpoint.c
+++ b/sound/usb/endpoint.c
@@ -911,6 +911,9 @@ static int endpoint_set_interface(struct snd_usb_audio *chip,
if (ep->iface_ref->altset == altset)
return 0;
+ /* already disconnected? */
+ if (unlikely(atomic_read(&chip->shutdown)))
+ return -ENODEV;
usb_audio_dbg(chip, "Setting usb interface %d:%d for EP 0x%x\n",
ep->iface, altset, ep->ep_num);