[alsa-devel] [PATCH] ALSA: pcm: Introduce protocol version field to sw_params
For controlling the new fields more strictly, add sw_params.proto field indicating the protocol version of the user-space. User-space should fill the SNDRV_PCM_VERSION value it's built with, then kernel can know whether the new fields should be evaluated or not.
And now tstamp_type field is evaluated only when the valid value is set there. This avoids the wrong override of tstamp_type to zero, which is SNDRV_PCM_TSTAMP_TYPE_GETTIMEOFDAY.
Signed-off-by: Takashi Iwai tiwai@suse.de --- include/uapi/sound/asound.h | 4 ++-- sound/core/pcm_native.c | 6 ++++-- 2 files changed, 6 insertions(+), 4 deletions(-)
diff --git a/include/uapi/sound/asound.h b/include/uapi/sound/asound.h index a7e062f91f39..c9fd199b9330 100644 --- a/include/uapi/sound/asound.h +++ b/include/uapi/sound/asound.h @@ -391,8 +391,8 @@ struct snd_pcm_sw_params { snd_pcm_uframes_t silence_threshold; /* min distance from noise for silence filling */ snd_pcm_uframes_t silence_size; /* silence block size */ snd_pcm_uframes_t boundary; /* pointers wrap point */ - unsigned int tstamp_type; /* timestamp type */ - int pads; /* alignment, reserved */ + unsigned int tstamp_type; /* timestamp type (req. proto >= 2.0.12) */ + unsigned int proto; /* protocol version */ unsigned char reserved[56]; /* reserved for future */ };
diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c index 81dedc381efd..8cd2f930ad0b 100644 --- a/sound/core/pcm_native.c +++ b/sound/core/pcm_native.c @@ -543,7 +543,8 @@ static int snd_pcm_sw_params(struct snd_pcm_substream *substream,
if (params->tstamp_mode > SNDRV_PCM_TSTAMP_LAST) return -EINVAL; - if (params->tstamp_type > SNDRV_PCM_TSTAMP_TYPE_LAST) + if (params->proto >= SNDRV_PROTOCOL_VERSION(2, 0, 12) && + params->tstamp_type > SNDRV_PCM_TSTAMP_TYPE_LAST) return -EINVAL; if (params->avail_min == 0) return -EINVAL; @@ -559,7 +560,8 @@ static int snd_pcm_sw_params(struct snd_pcm_substream *substream, err = 0; snd_pcm_stream_lock_irq(substream); runtime->tstamp_mode = params->tstamp_mode; - runtime->tstamp_type = params->tstamp_type; + if (params->proto >= SNDRV_PROTOCOL_VERSION(2, 0, 12)) + runtime->tstamp_type = params->tstamp_type; runtime->period_step = params->period_step; runtime->control->avail_min = params->avail_min; runtime->start_threshold = params->start_threshold;
Date 16.7.2014 17:54, Takashi Iwai wrote:
For controlling the new fields more strictly, add sw_params.proto field indicating the protocol version of the user-space. User-space should fill the SNDRV_PCM_VERSION value it's built with, then kernel can know whether the new fields should be evaluated or not.
And now tstamp_type field is evaluated only when the valid value is set there. This avoids the wrong override of tstamp_type to zero, which is SNDRV_PCM_TSTAMP_TYPE_GETTIMEOFDAY.
Signed-off-by: Takashi Iwai tiwai@suse.de
include/uapi/sound/asound.h | 4 ++-- sound/core/pcm_native.c | 6 ++++-- 2 files changed, 6 insertions(+), 4 deletions(-)
diff --git a/include/uapi/sound/asound.h b/include/uapi/sound/asound.h index a7e062f91f39..c9fd199b9330 100644 --- a/include/uapi/sound/asound.h +++ b/include/uapi/sound/asound.h @@ -391,8 +391,8 @@ struct snd_pcm_sw_params { snd_pcm_uframes_t silence_threshold; /* min distance from noise for silence filling */ snd_pcm_uframes_t silence_size; /* silence block size */ snd_pcm_uframes_t boundary; /* pointers wrap point */
- unsigned int tstamp_type; /* timestamp type */
- int pads; /* alignment, reserved */
- unsigned int tstamp_type; /* timestamp type (req. proto >= 2.0.12) */
- unsigned int proto; /* protocol version */
I would switch the positions of tstamp_type and proto... It seems logical that all new member added after proto are dependent on this value.
Jaroslav
At Thu, 17 Jul 2014 21:48:02 +0200, Jaroslav Kysela wrote:
Date 16.7.2014 17:54, Takashi Iwai wrote:
For controlling the new fields more strictly, add sw_params.proto field indicating the protocol version of the user-space. User-space should fill the SNDRV_PCM_VERSION value it's built with, then kernel can know whether the new fields should be evaluated or not.
And now tstamp_type field is evaluated only when the valid value is set there. This avoids the wrong override of tstamp_type to zero, which is SNDRV_PCM_TSTAMP_TYPE_GETTIMEOFDAY.
Signed-off-by: Takashi Iwai tiwai@suse.de
include/uapi/sound/asound.h | 4 ++-- sound/core/pcm_native.c | 6 ++++-- 2 files changed, 6 insertions(+), 4 deletions(-)
diff --git a/include/uapi/sound/asound.h b/include/uapi/sound/asound.h index a7e062f91f39..c9fd199b9330 100644 --- a/include/uapi/sound/asound.h +++ b/include/uapi/sound/asound.h @@ -391,8 +391,8 @@ struct snd_pcm_sw_params { snd_pcm_uframes_t silence_threshold; /* min distance from noise for silence filling */ snd_pcm_uframes_t silence_size; /* silence block size */ snd_pcm_uframes_t boundary; /* pointers wrap point */
- unsigned int tstamp_type; /* timestamp type */
- int pads; /* alignment, reserved */
- unsigned int tstamp_type; /* timestamp type (req. proto >= 2.0.12) */
- unsigned int proto; /* protocol version */
I would switch the positions of tstamp_type and proto... It seems logical that all new member added after proto are dependent on this value.
Yeah, right. I kept the order just because I thought of users of already published tree including tstamp_type. But, considering it again, since the branch is obviously for development-only, I guess this won't be too bad to swap the fields. (And thanks to the proto number check, the old branch wouldn't be broken too much.)
I'll swap the fields in the next revision.
thanks,
Takashi
participants (2)
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Jaroslav Kysela
-
Takashi Iwai