The recent kernel informs user-space when a driver requires the
explicit notification of appl_ptr update via a new flag,
SNDRV_PCM_INFO_SYNC_APPLPTR. When this flag is set, the user-space is
supposed to report the appl_ptr via SNDRV_PCM_IOCTL_SYNC_PTR ioctl.
This patch implements the requested behavior in the PCM hw plugin.
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
---
include/sound/asound.h | 1 +
src/pcm/pcm_hw.c | 27 +++++++++++++++++++++------
2 files changed, 22 insertions(+), 6 deletions(-)
diff --git a/include/sound/asound.h b/include/sound/asound.h
index fb8d7d7ef8ad..346db40e5932 100644
--- a/include/sound/asound.h
+++ b/include/sound/asound.h
@@ -268,6 +268,7 @@ typedef int __bitwise snd_pcm_subformat_t;
#define SNDRV_PCM_INFO_MMAP_VALID 0x00000002 /* period data are valid during transfer */
#define SNDRV_PCM_INFO_DOUBLE 0x00000004 /* Double buffering needed for PCM start/stop */
#define SNDRV_PCM_INFO_BATCH 0x00000010 /* double buffering */
+#define SNDRV_PCM_INFO_SYNC_APPLPTR 0x00000020 /* need the explicit sync of appl_ptr update */
#define SNDRV_PCM_INFO_INTERLEAVED 0x00000100 /* channels are interleaved */
#define SNDRV_PCM_INFO_NONINTERLEAVED 0x00000200 /* channels are not interleaved */
#define SNDRV_PCM_INFO_COMPLEX 0x00000400 /* complex frame organization (mmap only) */
diff --git a/src/pcm/pcm_hw.c b/src/pcm/pcm_hw.c
index 30cd5d0f6503..8855868f5ea2 100644
--- a/src/pcm/pcm_hw.c
+++ b/src/pcm/pcm_hw.c
@@ -91,6 +91,7 @@ typedef struct {
int fd;
int card, device, subdevice;
int sync_ptr_ioctl;
+ int sync_applptr;
volatile struct snd_pcm_mmap_status * mmap_status;
struct snd_pcm_mmap_control *mmap_control;
struct snd_pcm_sync_ptr *sync_ptr;
@@ -128,11 +129,13 @@ struct timespec snd_pcm_hw_fast_tstamp(snd_pcm_t *pcm)
}
#endif /* DOC_HIDDEN */
-static int sync_ptr1(snd_pcm_hw_t *hw, unsigned int flags)
+static int sync_ptr1(snd_pcm_hw_t *hw, struct snd_pcm_sync_ptr *ptr,
+ unsigned int flags)
{
int err;
- hw->sync_ptr->flags = flags;
- err = ioctl((hw)->fd, SNDRV_PCM_IOCTL_SYNC_PTR, (hw)->sync_ptr);
+
+ ptr->flags = flags;
+ err = ioctl(hw->fd, SNDRV_PCM_IOCTL_SYNC_PTR, ptr);
if (err < 0) {
err = -errno;
SYSMSG("SNDRV_PCM_IOCTL_SYNC_PTR failed (%i)", err);
@@ -143,7 +146,15 @@ static int sync_ptr1(snd_pcm_hw_t *hw, unsigned int flags)
static inline int sync_ptr(snd_pcm_hw_t *hw, unsigned int flags)
{
- return hw->sync_ptr ? sync_ptr1(hw, flags) : 0;
+ return hw->sync_ptr ? sync_ptr1(hw, hw->sync_ptr, flags) : 0;
+}
+
+/* explicit notification of appl_ptr update to kernel */
+static int sync_applptr(snd_pcm_hw_t *hw)
+{
+ struct snd_pcm_sync_ptr ptr;
+ ptr.c.control = *hw->mmap_control;
+ return sync_ptr1(hw, &ptr, 0);
}
static int snd_pcm_hw_clear_timer_queue(snd_pcm_hw_t *hw)
@@ -327,6 +338,7 @@ static int snd_pcm_hw_hw_params(snd_pcm_t *pcm, snd_pcm_hw_params_t * params)
SYSMSG("SNDRV_PCM_IOCTL_HW_PARAMS failed (%i)", err);
return err;
}
+ hw->sync_applptr = !!(params->info & SNDRV_PCM_INFO_SYNC_APPLPTR);
params->info &= ~0xf0000000;
if (pcm->tstamp_type != SND_PCM_TSTAMP_TYPE_GETTIMEOFDAY)
params->info |= SND_PCM_INFO_MONOTONIC;
@@ -568,7 +580,7 @@ static int snd_pcm_hw_hwsync(snd_pcm_t *pcm)
int fd = hw->fd, err;
if (SNDRV_PROTOCOL_VERSION(2, 0, 3) <= hw->version) {
if (hw->sync_ptr) {
- err = sync_ptr1(hw, SNDRV_PCM_SYNC_PTR_HWSYNC);
+ err = sync_ptr1(hw, hw->sync_ptr, SNDRV_PCM_SYNC_PTR_HWSYNC);
if (err < 0)
return err;
} else {
@@ -995,7 +1007,10 @@ static snd_pcm_sframes_t snd_pcm_hw_mmap_commit(snd_pcm_t *pcm,
snd_pcm_hw_t *hw = pcm->private_data;
snd_pcm_mmap_appl_forward(pcm, size);
- sync_ptr(hw, 0);
+ if (hw->sync_ptr)
+ sync_ptr(hw, 0);
+ else if (hw->sync_applptr)
+ sync_applptr(hw);
#ifdef DEBUG_MMAP
fprintf(stderr, "appl_forward: hw_ptr = %li, appl_ptr = %li, size = %li\n", *pcm->hw.ptr, *pcm->appl.ptr, size);
#endif
--
2.13.1
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