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authorWu Fengguang <fengguang.wu@intel.com>2010-09-29 12:18:41 +0800
committermalc <av1474@comtv.ru>2010-09-29 08:24:14 +0400
commitfd5723b385557bc77b93dfe5ab591813407686c0 (patch)
treed60523b1200ca6fc45f1c15f7dce9ea271f21421 /audio/paaudio.c
parent575c153f4f5cc23442e194619874de8ad4e6dd9c (diff)
pulse-audio: fix bug on updating rpos
Fix a rpos coordination bug between qpa_run_out() and qpa_thread_out(), which shows up as playback noises. qpa_run_out() qpa_thread_out loop N critical section 1 qpa_run_out() qpa_thread_out loop N doing pa_simple_write() qpa_run_out() qpa_thread_out loop N doing pa_simple_write() qpa_thread_out loop N critical section 2 qpa_thread_out loop N+1 critical section 1 qpa_run_out() qpa_thread_out loop N+1 doing pa_simple_write() In the above scheme, "qpa_thread_out loop N+1 critical section 1" will get the same rpos as the one used by "qpa_thread_out loop N critical section 1". So it will be reading dead samples from the old rpos. The rpos can only be updated back to qpa_thread_out when there is a qpa_run_out() run between two qpa_thread_out loops. normal sequence: qpa_thread_out: hw->rpos (X0) => local rpos => pa->rpos (X1) qpa_run_out: pa->rpos (X1) => hw->rpos (X1) qpa_thread_out: hw->rpos (X1) => local rpos => pa->rpos (X2) buggy sequence: qpa_thread_out: hw->rpos (X0) => local rpos => pa->rpos (X1) qpa_thread_out: hw->rpos (X0) => local rpos => pa->rpos (X1') Obviously qpa_run_out() shall be called at least once between any two qpa_thread_out loops (after pa->rpos is set), in order for the new qpa_thread_out loop to see the updated rpos. Setting pa->live to 0 does the trick. The next loop will have to wait for one qpa_run_out() invocation in order to get a non-zero pa->live and proceed. Signed-off-by: malc <av1474@comtv.ru> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Diffstat (limited to 'audio/paaudio.c')
-rw-r--r--audio/paaudio.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/audio/paaudio.c b/audio/paaudio.c
index 9118ece40c..ff71dac2a5 100644
--- a/audio/paaudio.c
+++ b/audio/paaudio.c
@@ -110,8 +110,8 @@ static void *qpa_thread_out (void *arg)
return NULL;
}
+ pa->live = 0;
pa->rpos = rpos;
- pa->live -= decr;
pa->decr += decr;
}