ALSA: usb-audio: Prevent printk ratelimiting from spamming kernel log while DEBUG...

This (widely used) construction:

if(printk_ratelimit())
	dev_dbg()

Causes the ratelimiting to spam the kernel log with the "callbacks suppressed"
message below, even while the dev_dbg it is supposed to rate limit wouldn't
print anything because DEBUG is not defined for this device.

[  533.803964] retire_playback_urb: 852 callbacks suppressed
[  538.807930] retire_playback_urb: 852 callbacks suppressed
[  543.811897] retire_playback_urb: 852 callbacks suppressed
[  548.815745] retire_playback_urb: 852 callbacks suppressed
[  553.819826] retire_playback_urb: 852 callbacks suppressed

So use dev_dbg_ratelimited() instead of this construction.

Signed-off-by: Sander Eikelenboom <linux@eikelenboom.it>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c
index 131336d..c62a165 100644 (file)
--- a/sound/usb/pcm.c
+++ b/sound/usb/pcm.c
@@ -1501,9 +1501,8 @@ static void retire_playback_urb(struct snd_usb_substream *subs,
         * The error should be lower than 2ms since the estimate relies
         * on two reads of a counter updated every ms.
         */
-       if (printk_ratelimit() &&
-           abs(est_delay - subs->last_delay) * 1000 > runtime->rate * 2)
-               dev_dbg(&subs->dev->dev,
+       if (abs(est_delay - subs->last_delay) * 1000 > runtime->rate * 2)
+               dev_dbg_ratelimited(&subs->dev->dev,
                        "delay: estimated %d, actual %d\n",
                        est_delay, subs->last_delay);