ALSA: snd-atmel-ac97c: set correct size for buffer hardware parameter

This patch will set a proper maximum bytes for the buffer, which is:
channels * bytes per sample * maximum periods * maximum bytes per period.

It also sets the minimum periods to 6, a value chosen from testing, with
a minimum of 6 periods the system has good time to fill in new audio
data without skipping.
Signed-off-by: NHans-Christian Egtvedt <hans-christian.egtvedt@atmel.com>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

sound/atmel/ac97c.c

@@ -151,10 +151,10 @@ static struct snd_pcm_hardware atmel_ac97c_hw = {
 	.rate_max		= 48000,
 	.channels_min		= 1,
 	.channels_max		= 2,
-	.buffer_bytes_max	= 64 * 4096,
+	.buffer_bytes_max	= 2 * 2 * 64 * 2048,
 	.period_bytes_min	= 4096,
 	.period_bytes_max	= 4096,
-	.periods_min		= 4,
+	.periods_min		= 6,
 	.periods_max		= 64,
 };