ALSA: snd-usb-caiaq: only warn once on streaming errors

Limit the number of printed warnings to one in case of streaming errors.
printk() happens to be expensive, especially in code called as often as
here.

Signed-off-by: Daniel Mack <daniel@caiaq.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

2 files changed, 4 insertions, 2 deletions

diff --git a/sound/usb/caiaq/caiaq-audio.c b/sound/usb/caiaq/caiaq-audio.c
index fc6d571eeac6..577b1129de0e 100644
--- a/sound/usb/caiaq/caiaq-audio.c
+++ b/sound/usb/caiaq/caiaq-audio.c
@@ -114,6 +114,7 @@ static int stream_start(struct snd_usb_caiaqdev *dev)
         dev->output_panic = 0;
         dev->first_packet = 1;
         dev->streaming = 1;
+        dev->warned = 0;
 
         for (i = 0; i < N_URBS; i++) {
                 ret = usb_submit_urb(dev->data_urbs_in[i], GFP_ATOMIC);
@@ -406,10 +407,11 @@ static void read_in_urb(struct snd_usb_caiaqdev *dev,
                 break;
         }
 
-        if (dev->input_panic || dev->output_panic) {
+        if ((dev->input_panic || dev->output_panic) && !dev->warned) {
                 debug("streaming error detected %s %s\n", 
                                 dev->input_panic ? "(input)" : "",
                                 dev->output_panic ? "(output)" : "");
+                dev->warned = 1;
         }
 }
 
diff --git a/sound/usb/caiaq/caiaq-device.h b/sound/usb/caiaq/caiaq-device.h
index 0560c327d996..098b194f7259 100644
--- a/sound/usb/caiaq/caiaq-device.h
+++ b/sound/usb/caiaq/caiaq-device.h
@@ -89,7 +89,7 @@ struct snd_usb_caiaqdev {
         int audio_out_buf_pos[MAX_STREAMS];
         int period_in_count[MAX_STREAMS];
         int period_out_count[MAX_STREAMS];
-        int input_panic, output_panic;
+        int input_panic, output_panic, warned;
         char *audio_in_buf, *audio_out_buf;
         unsigned int samplerates;