ALSA: usb-audio: Rate limit usb_set_interface error reporting

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]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Takashi Iwai <[email protected]>

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;
 	}
 

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...) \