qdsp5: audio: Protect common data between ADSP ISR and flush operation
During NEEDS_DATA or BUFFER_UPDATE event processing in ISR
context, if flush command is issued by application then
there is chance of concurrent access of some of the variables
shared between ISR and Process context. This may result in race
condition causing values of these shared variables to be
inconsistent.
Fix this by protecting these variables using spin lock. Also corrected
locking sequence order in encode drivers.
Change-Id: I06b4d08053ad13d1b118ab6f29e69e95b49d133f
Signed-off-by: Manish Dewangan <manish@codeaurora.org>
diff --git a/arch/arm/mach-msm/qdsp5/audio_pcm.c b/arch/arm/mach-msm/qdsp5/audio_pcm.c
index 02103fc..bd6e4a2 100644
--- a/arch/arm/mach-msm/qdsp5/audio_pcm.c
+++ b/arch/arm/mach-msm/qdsp5/audio_pcm.c
@@ -1,7 +1,7 @@
/* audio_pcm.c - pcm audio decoder driver
*
- * Copyright (c) 2009-2011, Code Aurora Forum. All rights reserved.
+ * Copyright (c) 2009-2012, Code Aurora Forum. All rights reserved.
*
* Based on the mp3 decoder driver in arch/arm/mach-msm/qdsp5/audio_mp3.c
*
@@ -639,12 +639,16 @@
static void audio_flush(struct audio *audio)
{
+ unsigned long flags;
+
+ spin_lock_irqsave(&audio->dsp_lock, flags);
audio->out[0].used = 0;
audio->out[1].used = 0;
audio->out_head = 0;
audio->out_tail = 0;
audio->reserved = 0;
audio->out_needed = 0;
+ spin_unlock_irqrestore(&audio->dsp_lock, flags);
atomic_set(&audio->out_bytes, 0);
}