[alsa-devel] [PATCH 5/5] ALSA: usb-audio: fix msleep timeout due to minimum resolution of task scheduling

[Takashi Sakamoto]

Depending on tick-related kernel configuration; e.g. HZ, task scheduler
necessarily has no guarantee for its minimum resolution against ~20 msec
msleep timeout.

This commit expands msleep timeout up to 20 msec with an optimistic view
to packet handling capability of the target device. 'checkpatch.pl'
generated below warning.

WARNING: msleep < 20ms can sleep for up to 20ms; see Documentation/timers/timers-howto.txt
+		msleep(15);

Fixes: d2bb390a2081 ("ALSA: usb-audio: Tascam US-16x08 DSP mixer quirk")
Signed-off-by: Takashi Sakamoto <o-takashi at sakamocchi.jp>
---
 sound/usb/mixer_us16x08.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sound/usb/mixer_us16x08.c b/sound/usb/mixer_us16x08.c
index d34dd1c..1c2d167 100644
--- a/sound/usb/mixer_us16x08.c
+++ b/sound/usb/mixer_us16x08.c
@@ -548,7 +548,7 @@ static int snd_us16x08_eqswitch_put(struct snd_kcontrol *kcontrol,
 		if (err < 0)
 			break;
 		store->val[b_idx][3][index] = val;
-		msleep(15);
+		msleep(20);
 	}
 
 	if (err > 0) {
-- 
2.9.3