From daa78c198ece1ec901ee565c869ee1a60a95061d Mon Sep 17 00:00:00 2001
From: Takashi Iwai <tiwai@suse.de>
Date: Tue, 4 Sep 2018 17:58:46 +0200
Subject: [PATCH] staging: bcm2835-audio: Add 10ms period constraint

commit 93c66acaf68b5247c3121a46a71ff6a70fc1d492 upstream.

It seems that the resolution of vc04 callback is in 10 msec; i.e. the
minimal period size is also 10 msec.

This patch adds the corresponding hw constraint.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Tested-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/staging/vc04_services/bcm2835-audio/bcm2835-pcm.c | 5 +++++
 1 file changed, 5 insertions(+)

--- a/drivers/staging/vc04_services/bcm2835-audio/bcm2835-pcm.c
+++ b/drivers/staging/vc04_services/bcm2835-audio/bcm2835-pcm.c
@@ -145,6 +145,11 @@ static int snd_bcm2835_playback_open_gen
 				   SNDRV_PCM_HW_PARAM_PERIOD_BYTES,
 				   16);
 
+	/* position update is in 10ms order */
+	snd_pcm_hw_constraint_minmax(runtime,
+				     SNDRV_PCM_HW_PARAM_PERIOD_TIME,
+				     10 * 1000, UINT_MAX);
+
 	chip->alsa_stream[idx] = alsa_stream;
 
 	chip->opened |= (1 << idx);
