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authorTakashi Iwai <tiwai@suse.de>2009-04-28 12:07:08 +0200
committerTakashi Iwai <tiwai@suse.de>2009-04-28 15:10:16 +0200
commit3e5b50165fd0be080044586f43fcdd460ed27610 (patch)
tree54e6ed455de1f011b7da25234553c4b61f4a3f08 /sound/core
parent2008f137e92220b98120c4803499cdddb2b0fb06 (diff)
downloadblackbird-op-linux-3e5b50165fd0be080044586f43fcdd460ed27610.tar.gz
blackbird-op-linux-3e5b50165fd0be080044586f43fcdd460ed27610.zip
ALSA: pcm core - Avoid jiffies check for devices with BATCH flag
The hardware devices with SNDRV_PCM_INFO_BATCH flag can't give the precise current position. And such hardwares have often big FIFO in addition to the ring buffer, and it screws up the jiffies check in pcm_lib.c. This patch adds a simple check of info flag so that the driver skips the jiffies check in snd_pcm_period_elapsed() when BATCH flag is set. Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/core')
-rw-r--r--sound/core/pcm_lib.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c
index 63d088f2265f..a2a792c18c40 100644
--- a/sound/core/pcm_lib.c
+++ b/sound/core/pcm_lib.c
@@ -249,6 +249,12 @@ static int snd_pcm_update_hw_ptr_interrupt(struct snd_pcm_substream *substream)
new_hw_ptr = hw_base + pos;
}
}
+ /* Skip the jiffies check for hardwares with BATCH flag.
+ * Such hardware usually just increases the position at each IRQ,
+ * thus it can't give any strange position.
+ */
+ if (runtime->hw.info & SNDRV_PCM_INFO_BATCH)
+ goto no_jiffies_check;
hdelta = new_hw_ptr - old_hw_ptr;
jdelta = jiffies - runtime->hw_ptr_jiffies;
if (((hdelta * HZ) / runtime->rate) > jdelta + HZ/100) {
@@ -272,6 +278,7 @@ static int snd_pcm_update_hw_ptr_interrupt(struct snd_pcm_substream *substream)
hw_base -= hw_base % runtime->buffer_size;
delta = 0;
}
+ no_jiffies_check:
if (delta > runtime->period_size + runtime->period_size / 2) {
hw_ptr_error(substream,
"Lost interrupts? "
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