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@xxxxxxx>
> Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
Acked-by: Shengjiu Wang <shengjiu.wang@xxxxxxx>
> ---
> 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
