@@ -165,6 +165,20 @@ static int query_status_and_control_data(snd_pcm_hw_t *hw)
SNDRV_PCM_SYNC_PTR_AVAIL_MIN);
}
+static int query_status_data(snd_pcm_hw_t *hw)
+{
+ if (!hw->mmap_status_fallbacked)
+ return 0;
+
+ /*
+ * Query both of control/status data to avoid unexpected change of
+ * control data in kernel space.
+ */
+ return sync_ptr1(hw,
+ SNDRV_PCM_SYNC_PTR_APPL |
+ SNDRV_PCM_SYNC_PTR_AVAIL_MIN);
+}
+
static int snd_pcm_hw_clear_timer_queue(snd_pcm_hw_t *hw)
{
if (hw->period_timer_need_poll) {
@@ -349,7 +363,7 @@ static int snd_pcm_hw_hw_params(snd_pcm_t *pcm, snd_pcm_hw_params_t * params)
params->info &= ~0xf0000000;
if (pcm->tstamp_type != SND_PCM_TSTAMP_TYPE_GETTIMEOFDAY)
params->info |= SND_PCM_INFO_MONOTONIC;
- return sync_ptr(hw, 0);
+ return query_status_data(hw);
}
static void snd_pcm_hw_close_timer(snd_pcm_hw_t *hw)
@@ -556,7 +570,7 @@ static int snd_pcm_hw_status(snd_pcm_t *pcm, snd_pcm_status_t * status)
static snd_pcm_state_t snd_pcm_hw_state(snd_pcm_t *pcm)
{
snd_pcm_hw_t *hw = pcm->private_data;
- int err = sync_ptr(hw, 0);
+ int err = query_status_data(hw);
if (err < 0)
return err;
return (snd_pcm_state_t) hw->mmap_status->state;
@@ -1064,7 +1078,7 @@ static snd_pcm_sframes_t snd_pcm_hw_avail_update(snd_pcm_t *pcm)
snd_pcm_hw_t *hw = pcm->private_data;
snd_pcm_uframes_t avail;
- sync_ptr(hw, 0);
+ query_status_data(hw);
avail = snd_pcm_mmap_avail(pcm);
switch (FAST_PCM_STATE(hw)) {
case SNDRV_PCM_STATE_RUNNING:
When mapping status data successfully, mapped page includes status data for applications. In this case, applications have no need to call ioctl(2) with SNDRV_PCM_IOCTL_SYNC_PTR. However, in current implementation, when map of control data is unavailable, applications execute the ioctl(2). This is inconvenient for some cases that applications require to query status only. This commit adds a helper function to query status data without issuing the control in fallback mode from failure of status mmap. Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> --- src/pcm/pcm_hw.c | 20 +++++++++++++++++--- 1 file changed, 17 insertions(+), 3 deletions(-)