ALSA: hdspm - Constrain periods to 2 on older cards

RME RayDAT and AIO use a fixed buffer size of 16384 samples. With period
sizes of 32-4096, this translates to 4-512 periods.

The older RME cards have a variable buffer size but require exactly two
periods.

This patch enforces nperiods=2 on those cards.

Signed-off-by: Adrian Knoth <adi@drcomp.erfurt.thur.de>
Cc: <stable@vger.kernel.org> # 2.6.39+
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 6 insertions, 0 deletions

diff --git a/sound/pci/rme9652/hdspm.c b/sound/pci/rme9652/hdspm.c
index 2c363fdca9fd..ca67f896d117 100644
--- a/sound/pci/rme9652/hdspm.c
+++ b/sound/pci/rme9652/hdspm.c
@@ -6082,6 +6082,9 @@ static int snd_hdspm_playback_open(struct snd_pcm_substream *substream)
                 snd_pcm_hw_constraint_minmax(runtime,
                                              SNDRV_PCM_HW_PARAM_PERIOD_SIZE,
                                              64, 8192);
+                snd_pcm_hw_constraint_minmax(runtime,
+                                             SNDRV_PCM_HW_PARAM_PERIODS,
+                                             2, 2);
                 break;
         }
 
@@ -6156,6 +6159,9 @@ static int snd_hdspm_capture_open(struct snd_pcm_substream *substream)
                 snd_pcm_hw_constraint_minmax(runtime,
                                              SNDRV_PCM_HW_PARAM_PERIOD_SIZE,
                                              64, 8192);
+                snd_pcm_hw_constraint_minmax(runtime,
+                                             SNDRV_PCM_HW_PARAM_PERIODS,
+                                             2, 2);
                 break;
         }