The commit 1a9bd0f04481 ("pcm: direct: Fix for sync issue on xrun recover") introduced a new field "recoveries" in snd_pcm_direct_share_t. Unfortunately this caused two issues:

- It changed the size of the struct which is used as the magic key - The struct size differs between 32bit and 64bit due to alignment

The former brought the incompatibility with the older alsa-lib, e.g. when you run an app with an older alsa-lib via LD_PRELOAD, it doesn't work any longer.

The latter is more serious, it disallows running 32bit apps dmix with 64bit together.

As a workaround, put recoveries field to the unused field "s.xfer_align", so that the struct is in an old form.

This is a one-time workaround, and we may need to reconsider more about a breakage in future...

Reported-and-tested-by: Cheng Sun chengsun9@gmail.com Signed-off-by: Takashi Iwai tiwai@suse.de --- src/pcm/pcm_direct.c | 8 ++++---- src/pcm/pcm_direct.h | 3 +-- 2 files changed, 5 insertions(+), 6 deletions(-)

diff --git a/src/pcm/pcm_direct.c b/src/pcm/pcm_direct.c index 89468d3537d0..43702601b0f2 100644 --- a/src/pcm/pcm_direct.c +++ b/src/pcm/pcm_direct.c @@ -615,7 +615,7 @@ int snd_pcm_direct_slave_recover(snd_pcm_direct_t *direct) } return ret; } - direct->shmptr->recoveries++; + direct->shmptr->s.recoveries++; semerr = snd_pcm_direct_semaphore_up(direct, DIRECT_IPC_SEM_CLIENT); if (semerr < 0) { @@ -631,11 +631,11 @@ int snd_pcm_direct_slave_recover(snd_pcm_direct_t *direct) */ int snd_pcm_direct_client_chk_xrun(snd_pcm_direct_t *direct, snd_pcm_t *pcm) { - if (direct->shmptr->recoveries != direct->recoveries) { + if (direct->shmptr->s.recoveries != direct->recoveries) { /* no matter how many xruns we missed - * so don't increment but just update to actual counter */ - direct->recoveries = direct->shmptr->recoveries; + direct->recoveries = direct->shmptr->s.recoveries; pcm->fast_ops->drop(pcm); /* trigger_tstamp update is missing in drop callbacks */ gettimestamp(&direct->trigger_tstamp, pcm->tstamp_type); @@ -1539,7 +1539,7 @@ int snd_pcm_direct_open_secondary_client(snd_pcm_t **spcmp, snd_pcm_direct_t *dm dmix->slave_buffer_size = spcm->buffer_size; dmix->slave_period_size = dmix->shmptr->s.period_size; dmix->slave_boundary = spcm->boundary; - dmix->recoveries = dmix->shmptr->recoveries; + dmix->recoveries = dmix->shmptr->s.recoveries;

ret = snd_pcm_mmap(spcm); if (ret < 0) { diff --git a/src/pcm/pcm_direct.h b/src/pcm/pcm_direct.h index 24e85f096310..582f055a5451 100644 --- a/src/pcm/pcm_direct.h +++ b/src/pcm/pcm_direct.h @@ -66,7 +66,6 @@ typedef struct { char socket_name[256]; /* name of communication socket */ snd_pcm_type_t type; /* PCM type (currently only hw) */ int use_server; - unsigned int recoveries; /* no of executed recoveries on slave*/ struct { unsigned int format; snd_interval_t rate; @@ -95,7 +94,7 @@ typedef struct { unsigned int stop_threshold; unsigned int silence_threshold; unsigned int silence_size; - unsigned int xfer_align; /* not used */ + unsigned int recoveries; /* no of executed recoveries on slave*/ unsigned long long boundary; unsigned int info; unsigned int msbits;