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| author | Takashi Iwai <tiwai@suse.de> | 2017-05-19 18:31:03 +0200 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2017-05-25 23:34:45 +0200 |
| commit | 9629581258cb520a413a4240fc4254a45e0a81df (patch) | |
| tree | 5d6e56291c1204c7ae743f34da3c03adde17b3a9 | |
| parent | 6dbaf8b913f2976ee776beb7c8bb0c52c7066ced (diff) | |
| download | linux-stable-9629581258cb520a413a4240fc4254a45e0a81df.tar.gz linux-stable-9629581258cb520a413a4240fc4254a45e0a81df.tar.bz2 linux-stable-9629581258cb520a413a4240fc4254a45e0a81df.zip | |
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>
| -rw-r--r-- | include/sound/pcm-indirect.h | 10 |
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; } /* |