At Thu, 24 Apr 2014 20:40:06 +0600, Alexander E. Patrakov wrote:
When forwarding or rewinding, the frame counter was not updated. This could result in corrupted channel status words or misplaced Z-type preamble.
Signed-off-by: Alexander E. Patrakov patrakov@gmail.com
v2: As suggested by David Henningsson, patch a copy of snd_pcm_plugin_fast_ops at runtime instead of making all plugin finctions non-static. But, contrary to his proposal, I made fast_ops just a part of struct snd_pcm_iec958, because the needed lifetime is exactly the same.
I still have no hardware to test this, and I strongly suspect that the patch is wrong, because nobody else uses dynamic allocation of fast_ops. A potentially suspicious operation would be to place a plug on top of this, because plug copies fast_ops around. However, each time it closes a slave, it also resets fast_ops to something sane, or at least I think so.
The embedded fast_ops should work fine, so I applied the patch as is now. Let's see whether it really fixes the issues properly...
thanks,
Takashi
src/pcm/pcm_iec958.c | 37 ++++++++++++++++++++++++++++++++++++- src/pcm/pcm_plugin.c | 4 ++-- src/pcm/pcm_plugin.h | 6 ++++++ 3 files changed, 44 insertions(+), 3 deletions(-)
diff --git a/src/pcm/pcm_iec958.c b/src/pcm/pcm_iec958.c index d81b0a1..0c61fc1 100644 --- a/src/pcm/pcm_iec958.c +++ b/src/pcm/pcm_iec958.c @@ -62,6 +62,7 @@ struct snd_pcm_iec958 { unsigned char status[24]; unsigned int byteswap; unsigned char preamble[3]; /* B/M/W or Z/X/Y */
- snd_pcm_fast_ops_t fops;
};
enum { PREAMBLE_Z, PREAMBLE_X, PREAMBLE_Y }; @@ -416,6 +417,35 @@ static void snd_pcm_iec958_dump(snd_pcm_t *pcm, snd_output_t *out) snd_pcm_dump(iec->plug.gen.slave, out); }
+static snd_pcm_sframes_t snd_pcm_iec958_rewind(snd_pcm_t *pcm, snd_pcm_uframes_t frames) +{
- unsigned int counter_decrement;
- snd_pcm_iec958_t *iec = pcm->private_data;
- snd_pcm_sframes_t result = snd_pcm_plugin_rewind(pcm, frames);
- if (result <= 0)
return result;- counter_decrement = result % 192;
- iec->counter += 192 - counter_decrement;
- iec->counter %= 192;
- return result;
+}
+static snd_pcm_sframes_t snd_pcm_iec958_forward(snd_pcm_t *pcm, snd_pcm_uframes_t frames)
+{
- unsigned int counter_increment;
- snd_pcm_iec958_t *iec = pcm->private_data;
- snd_pcm_sframes_t result = snd_pcm_plugin_rewind(pcm, frames);
- if (result <= 0)
return result;- counter_increment = result % 192;
- iec->counter += counter_increment;
- iec->counter %= 192;
- return result;
+}
static const snd_pcm_ops_t snd_pcm_iec958_ops = { .close = snd_pcm_generic_close, .info = snd_pcm_generic_info, @@ -495,7 +525,12 @@ int snd_pcm_iec958_open(snd_pcm_t **pcmp, const char *name, snd_pcm_format_t sfo return err; } pcm->ops = &snd_pcm_iec958_ops;
- pcm->fast_ops = &snd_pcm_plugin_fast_ops;
- iec->fops = snd_pcm_plugin_fast_ops;
- iec->fops.rewind = snd_pcm_iec958_rewind;
- iec->fops.forward = snd_pcm_iec958_forward;
- pcm->fast_ops = &iec->fops;
- pcm->private_data = iec; pcm->poll_fd = slave->poll_fd; pcm->poll_events = slave->poll_events;
diff --git a/src/pcm/pcm_plugin.c b/src/pcm/pcm_plugin.c index 17157e8..4ddf10c 100644 --- a/src/pcm/pcm_plugin.c +++ b/src/pcm/pcm_plugin.c @@ -201,7 +201,7 @@ static snd_pcm_sframes_t snd_pcm_plugin_rewindable(snd_pcm_t *pcm) return snd_pcm_mmap_hw_avail(pcm); }
-static snd_pcm_sframes_t snd_pcm_plugin_rewind(snd_pcm_t *pcm, snd_pcm_uframes_t frames) +snd_pcm_sframes_t snd_pcm_plugin_rewind(snd_pcm_t *pcm, snd_pcm_uframes_t frames) { snd_pcm_plugin_t *plugin = pcm->private_data; snd_pcm_sframes_t n = snd_pcm_mmap_hw_avail(pcm); @@ -229,7 +229,7 @@ static snd_pcm_sframes_t snd_pcm_plugin_forwardable(snd_pcm_t *pcm) return snd_pcm_mmap_avail(pcm); }
-static snd_pcm_sframes_t snd_pcm_plugin_forward(snd_pcm_t *pcm, snd_pcm_uframes_t frames) +snd_pcm_sframes_t snd_pcm_plugin_forward(snd_pcm_t *pcm, snd_pcm_uframes_t frames) { snd_pcm_plugin_t *plugin = pcm->private_data; snd_pcm_sframes_t n = snd_pcm_mmap_avail(pcm); diff --git a/src/pcm/pcm_plugin.h b/src/pcm/pcm_plugin.h index 7ee7c7f..19e82c3 100644 --- a/src/pcm/pcm_plugin.h +++ b/src/pcm/pcm_plugin.h @@ -58,8 +58,14 @@ typedef struct { snd1_pcm_plugin_undo_read_generic #define snd_pcm_plugin_undo_write_generic \ snd1_pcm_plugin_undo_write_generic +#define snd_pcm_plugin_rewind \
- snd1_pcm_plugin_rewind
+#define snd_pcm_plugin_forward \
- snd1_pcm_plugin_forward
void snd_pcm_plugin_init(snd_pcm_plugin_t *plugin); +snd_pcm_sframes_t snd_pcm_plugin_rewind(snd_pcm_t *pcm, snd_pcm_uframes_t frames); +snd_pcm_sframes_t snd_pcm_plugin_forward(snd_pcm_t *pcm, snd_pcm_uframes_t frames);
extern const snd_pcm_fast_ops_t snd_pcm_plugin_fast_ops;
-- 1.9.2
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