[34-longterm 039/247] ALSA : au88x0 - Limit number of channels to fix Oops via OSS emu

Paul Gortmaker
2011-06-23T17:22:32Z

From: Raymond Yau <superquad.vortex2@gmail.com>

-------------------
This is a commit scheduled for the next v2.6.34 longterm release.
If you see a problem with using this for longterm, please comment.
-------------------

commit d9ab344336f74c012f6643ed3d1ad8ca0136de3b upstream.

Fix playback/capture channels patch to change supported playback
channels of au8830 to 1,2,4 and capture channels to 1,2.
This prevent oops when oss emulation use SNDCTL_DSP_CHANNELS to
set 3 Channels

Signed-off-by: Raymond Yau <superquad.vortex2@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
---
sound/pci/au88x0/au88x0_pcm.c | 24 ++++++++++++++++++++----
1 files changed, 20 insertions(+), 4 deletions(-)

diff --git a/sound/pci/au88x0/au88x0_pcm.c b/sound/pci/au88x0/au88x0_pcm.c
index b9d2f20..5439d66 100644
--- a/sound/pci/au88x0/au88x0_pcm.c
+++ b/sound/pci/au88x0/au88x0_pcm.c
@@ -42,11 +42,7 @@ static struct snd_pcm_hardware snd_vortex_playback_hw_adb = {
.rate_min = 5000,
.rate_max = 48000,
.channels_min = 1,
-#ifdef CHIP_AU8830
- .channels_max = 4,
-#else
.channels_max = 2,
-#endif
.buffer_bytes_max = 0x10000,
.period_bytes_min = 0x1,
.period_bytes_max = 0x1000,
@@ -115,6 +111,17 @@ static struct snd_pcm_hardware snd_vortex_playback_hw_wt = {
.periods_max = 64,
};
#endif
+#ifdef CHIP_AU8830
+static unsigned int au8830_channels[3] = {
+ 1, 2, 4,
+};
+
+static struct snd_pcm_hw_constraint_list hw_constraints_au8830_channels = {
+ .count = ARRAY_SIZE(au8830_channels),
+ .list = au8830_channels,
+ .mask = 0,
+};
+#endif
/* open callback */
static int snd_vortex_pcm_open(struct snd_pcm_substream *substream)
{
@@ -156,6 +163,15 @@ static int snd_vortex_pcm_open(struct snd_pcm_substream *substream)
if (VORTEX_PCM_TYPE(substream->pcm) == VORTEX_PCM_ADB
|| VORTEX_PCM_TYPE(substream->pcm) == VORTEX_PCM_I2S)
runtime->hw = snd_vortex_playback_hw_adb;
+#ifdef CHIP_AU8830
+ if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK &&
+ VORTEX_PCM_TYPE(substream->pcm) == VORTEX_PCM_ADB) {
+ runtime->hw.channels_max = 4;
+ snd_pcm_hw_constraint_list(runtime, 0,
+ SNDRV_PCM_HW_PARAM_CHANNELS,
+ &hw_constraints_au8830_channels);
+ }
+#endif
substream->runtime->private_data = NULL;
}
#ifndef CHIP_AU8810
--
1.7.4.4