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authorTakashi Iwai <tiwai@suse.de>2017-05-19 18:31:03 +0200
committerTakashi Iwai <tiwai@suse.de>2017-05-25 23:34:45 +0200
commit9629581258cb520a413a4240fc4254a45e0a81df (patch)
tree5d6e56291c1204c7ae743f34da3c03adde17b3a9 /include/sound
parent6dbaf8b913f2976ee776beb7c8bb0c52c7066ced (diff)
ALSA: pcm: Fix negative appl_ptr handling in pcm-indirect helpers
The indirect-PCM helper codes have an implicit assumption that the appl_ptr always increases. But the PCM core may deal with the decrement of appl_ptr via rewind ioctls, and it may screw up the buffer pointer management. This patch adds the negative appl_ptr diff in transfer functions and let returning an error instead of always accepting the appl_ptr updates. The callers are usually PCM ack callbacks, and they pass the error to the upper layer accordingly. Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'include/sound')
-rw-r--r--include/sound/pcm-indirect.h10
1 files changed, 8 insertions, 2 deletions
diff --git a/include/sound/pcm-indirect.h b/include/sound/pcm-indirect.h
index 1df7acaaa535..7ade285328cf 100644
--- a/include/sound/pcm-indirect.h
+++ b/include/sound/pcm-indirect.h
@@ -43,7 +43,7 @@ typedef void (*snd_pcm_indirect_copy_t)(struct snd_pcm_substream *substream,
/*
* helper function for playback ack callback
*/
-static inline void
+static inline int
snd_pcm_indirect_playback_transfer(struct snd_pcm_substream *substream,
struct snd_pcm_indirect *rec,
snd_pcm_indirect_copy_t copy)
@@ -56,6 +56,8 @@ snd_pcm_indirect_playback_transfer(struct snd_pcm_substream *substream,
if (diff) {
if (diff < -(snd_pcm_sframes_t) (runtime->boundary / 2))
diff += runtime->boundary;
+ if (diff < 0)
+ return -EINVAL;
rec->sw_ready += (int)frames_to_bytes(runtime, diff);
rec->appl_ptr = appl_ptr;
}
@@ -82,6 +84,7 @@ snd_pcm_indirect_playback_transfer(struct snd_pcm_substream *substream,
rec->hw_ready += bytes;
rec->sw_ready -= bytes;
}
+ return 0;
}
/*
@@ -109,7 +112,7 @@ snd_pcm_indirect_playback_pointer(struct snd_pcm_substream *substream,
/*
* helper function for capture ack callback
*/
-static inline void
+static inline int
snd_pcm_indirect_capture_transfer(struct snd_pcm_substream *substream,
struct snd_pcm_indirect *rec,
snd_pcm_indirect_copy_t copy)
@@ -121,6 +124,8 @@ snd_pcm_indirect_capture_transfer(struct snd_pcm_substream *substream,
if (diff) {
if (diff < -(snd_pcm_sframes_t) (runtime->boundary / 2))
diff += runtime->boundary;
+ if (diff < 0)
+ return -EINVAL;
rec->sw_ready -= frames_to_bytes(runtime, diff);
rec->appl_ptr = appl_ptr;
}
@@ -147,6 +152,7 @@ snd_pcm_indirect_capture_transfer(struct snd_pcm_substream *substream,
rec->hw_ready -= bytes;
rec->sw_ready += bytes;
}
+ return 0;
}
/*