RE: [PATCH alsa-lib v2 3/3] pcm: direct: Check xrun/suspend before the slave hwptr update
Hi
The xrun/suspend may happen at any time and we should check it right after the slave hwptr update (but before the actual sync_ptr update in direct pcm side). Otherwise the hwptr value may be screwed and get unexpected large read/write.
Reported-by: S.J. Wang shengjiu.wang@nxp.com Signed-off-by: Takashi Iwai tiwai@suse.de
Acked-by: Shengjiu Wang shengjiu.wang@nxp.com
src/pcm/pcm_dmix.c | 8 +++++--- src/pcm/pcm_dshare.c | 8 +++++--- src/pcm/pcm_dsnoop.c | 6 +++--- 3 files changed, 13 insertions(+), 9 deletions(-)
diff --git a/src/pcm/pcm_dmix.c b/src/pcm/pcm_dmix.c index d00d53bef604..c6cb47f0f840 100644 --- a/src/pcm/pcm_dmix.c +++ b/src/pcm/pcm_dmix.c @@ -424,15 +424,17 @@ static int snd_pcm_dmix_sync_ptr0(snd_pcm_t *pcm, snd_pcm_uframes_t slave_hw_ptr static int snd_pcm_dmix_sync_ptr(snd_pcm_t *pcm) { snd_pcm_direct_t *dmix = pcm->private_data;
snd_pcm_uframes_t slave_hw_ptr; int err;
if (dmix->slowptr)
snd_pcm_hwsync(dmix->spcm);
slave_hw_ptr = *dmix->spcm->hw.ptr; err = snd_pcm_direct_check_xrun(dmix, pcm); if (err < 0) return err;
if (dmix->slowptr)
snd_pcm_hwsync(dmix->spcm);
return snd_pcm_dmix_sync_ptr0(pcm, *dmix->spcm->hw.ptr);
return snd_pcm_dmix_sync_ptr0(pcm, slave_hw_ptr);
}
/* diff --git a/src/pcm/pcm_dshare.c b/src/pcm/pcm_dshare.c index 0ff43a90d270..461adafc77f8 100644 --- a/src/pcm/pcm_dshare.c +++ b/src/pcm/pcm_dshare.c @@ -199,15 +199,17 @@ static int snd_pcm_dshare_sync_ptr0(snd_pcm_t *pcm, snd_pcm_uframes_t slave_hw_p static int snd_pcm_dshare_sync_ptr(snd_pcm_t *pcm) { snd_pcm_direct_t *dshare = pcm->private_data;
snd_pcm_uframes_t slave_hw_ptr; int err;
if (dshare->slowptr)
snd_pcm_hwsync(dshare->spcm);
slave_hw_ptr = *dshare->spcm->hw.ptr; err = snd_pcm_direct_check_xrun(dshare, pcm); if (err < 0) return err;
if (dshare->slowptr)
snd_pcm_hwsync(dshare->spcm);
return snd_pcm_dshare_sync_ptr0(pcm, *dshare->spcm->hw.ptr);
return snd_pcm_dshare_sync_ptr0(pcm, slave_hw_ptr);
}
/* diff --git a/src/pcm/pcm_dsnoop.c b/src/pcm/pcm_dsnoop.c index 729ff447b41f..9abbbef2c1b6 100644 --- a/src/pcm/pcm_dsnoop.c +++ b/src/pcm/pcm_dsnoop.c @@ -134,14 +134,14 @@ static int snd_pcm_dsnoop_sync_ptr(snd_pcm_t *pcm) snd_pcm_sframes_t diff; int err;
err = snd_pcm_direct_check_xrun(dsnoop, pcm);
if (err < 0)
return err; if (dsnoop->slowptr) snd_pcm_hwsync(dsnoop->spcm); old_slave_hw_ptr = dsnoop->slave_hw_ptr; snoop_timestamp(pcm); slave_hw_ptr = dsnoop->slave_hw_ptr;
err = snd_pcm_direct_check_xrun(dsnoop, pcm);
if (err < 0)
return err; diff = pcm_frame_diff(slave_hw_ptr, old_slave_hw_ptr, dsnoop-
slave_boundary);
if (diff == 0) /* fast path */ return 0;
-- 2.34.1
participants (1)
-
S.J. Wang