[ALSA] Remove PCM xfer_align sw params

The xfer_align sw_params parameter has never been used in a sane manner,
and no one understands what this does exactly.  The current
implementation looks also buggy because it allows write of shorter size
than xfer_align.  So, if you do partial writes, the write isn't actually
aligned at all.
Removing this parameter will make some pcm_lib_* code more readable
(and less buggy).

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>

diff --git a/Documentation/sound/alsa/DocBook/writing-an-alsa-driver.tmpl b/Documentation/sound/alsa/DocBook/writing-an-alsa-driver.tmpl
index 48e4053..835e320 100644 (file)
--- a/Documentation/sound/alsa/DocBook/writing-an-alsa-driver.tmpl
+++ b/Documentation/sound/alsa/DocBook/writing-an-alsa-driver.tmpl
@@ -2188,7 +2188,6 @@ struct _snd_pcm_runtime {
        struct timespec tstamp_mode;    /* mmap timestamp is updated */
        unsigned int period_step;
        unsigned int sleep_min;         /* min ticks to sleep */
-       snd_pcm_uframes_t xfer_align;   /* xfer size need to be a multiple */
        snd_pcm_uframes_t start_threshold;
        snd_pcm_uframes_t stop_threshold;
        snd_pcm_uframes_t silence_threshold; /* Silence filling happens when

diff --git a/include/sound/asound.h b/include/sound/asound.h
index ee753d7..069d912 100644 (file)
--- a/include/sound/asound.h
+++ b/include/sound/asound.h
@@ -363,7 +363,7 @@ struct snd_pcm_sw_params {
        unsigned int period_step;
        unsigned int sleep_min;                 /* min ticks to sleep */
        snd_pcm_uframes_t avail_min;            /* min avail frames for wakeup */
-       snd_pcm_uframes_t xfer_align;           /* xfer size need to be a multiple */
+       snd_pcm_uframes_t xfer_align;           /* obsolete: xfer size need to be a multiple */
        snd_pcm_uframes_t start_threshold;      /* min hw_avail frames for automatic start */
        snd_pcm_uframes_t stop_threshold;       /* min avail frames for automatic stop */
        snd_pcm_uframes_t silence_threshold;    /* min distance from noise for silence filling */

diff --git a/include/sound/pcm.h b/include/sound/pcm.h
index 65f6362..1270cbc 100644 (file)
--- a/include/sound/pcm.h
+++ b/include/sound/pcm.h
@@ -287,7 +287,6 @@ struct snd_pcm_runtime {
        int tstamp_mode;                /* mmap timestamp is updated */
        unsigned int period_step;
        unsigned int sleep_min;         /* min ticks to sleep */
-       snd_pcm_uframes_t xfer_align;   /* xfer size need to be a multiple */
        snd_pcm_uframes_t start_threshold;
        snd_pcm_uframes_t stop_threshold;
        snd_pcm_uframes_t silence_threshold; /* Silence filling happens when

diff --git a/sound/core/oss/pcm_oss.c b/sound/core/oss/pcm_oss.c
index d0c4ceb..be089cc 100644 (file)
--- a/sound/core/oss/pcm_oss.c
+++ b/sound/core/oss/pcm_oss.c
@@ -988,7 +988,6 @@ static int snd_pcm_oss_change_params(struct snd_pcm_substream *substream)
        sw_params->sleep_min = 0;
        sw_params->avail_min = substream->stream == SNDRV_PCM_STREAM_PLAYBACK ?
                1 : runtime->period_size;
-       sw_params->xfer_align = 1;
        if (atomic_read(&substream->mmap_count) ||
            substream->oss.setup.nosilence) {
                sw_params->silence_threshold = 0;

diff --git a/sound/core/pcm.c b/sound/core/pcm.c
index cf9b949..97cb681 100644 (file)
--- a/sound/core/pcm.c
+++ b/sound/core/pcm.c
@@ -389,7 +389,6 @@ static void snd_pcm_substream_proc_sw_params_read(struct snd_info_entry *entry,
        snd_iprintf(buffer, "period_step: %u\n", runtime->period_step);
        snd_iprintf(buffer, "sleep_min: %u\n", runtime->sleep_min);
        snd_iprintf(buffer, "avail_min: %lu\n", runtime->control->avail_min);
-       snd_iprintf(buffer, "xfer_align: %lu\n", runtime->xfer_align);
        snd_iprintf(buffer, "start_threshold: %lu\n", runtime->start_threshold);
        snd_iprintf(buffer, "stop_threshold: %lu\n", runtime->stop_threshold);
        snd_iprintf(buffer, "silence_threshold: %lu\n", runtime->silence_threshold);

diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c
index f9f9b3f..c1c1556 100644 (file)
--- a/sound/core/pcm_lib.c
+++ b/sound/core/pcm_lib.c
@@ -1628,8 +1628,6 @@ static snd_pcm_sframes_t snd_pcm_lib_write1(struct snd_pcm_substream *substream,
 
        if (size == 0)
                return 0;
-       if (size > runtime->xfer_align)
-               size -= size % runtime->xfer_align;
 
        snd_pcm_stream_lock_irq(substream);
        switch (runtime->status->state) {
@@ -1657,9 +1655,7 @@ static snd_pcm_sframes_t snd_pcm_lib_write1(struct snd_pcm_substream *substream,
                avail = snd_pcm_playback_avail(runtime);
                if (!avail ||
                    (snd_pcm_running(substream) &&
-                    ((avail < runtime->control->avail_min && size > avail) ||
-                     (size >= runtime->xfer_align &&
-                      avail < runtime->xfer_align)))) {
+                    (avail < runtime->control->avail_min && size > avail))) {
                        wait_queue_t wait;
                        enum { READY, SIGNALED, ERROR, SUSPENDED, EXPIRED, DROPPED } state;
                        long tout;
@@ -1731,8 +1727,6 @@ static snd_pcm_sframes_t snd_pcm_lib_write1(struct snd_pcm_substream *substream,
                                break;
                        }
                }
-               if (avail > runtime->xfer_align)
-                       avail -= avail % runtime->xfer_align;
                frames = size > avail ? avail : size;
                cont = runtime->buffer_size - runtime->control->appl_ptr % runtime->buffer_size;
                if (frames > cont)
@@ -1900,8 +1894,6 @@ static snd_pcm_sframes_t snd_pcm_lib_read1(struct snd_pcm_substream *substream,
 
        if (size == 0)
                return 0;
-       if (size > runtime->xfer_align)
-               size -= size % runtime->xfer_align;
 
        snd_pcm_stream_lock_irq(substream);
        switch (runtime->status->state) {
@@ -1936,12 +1928,12 @@ static snd_pcm_sframes_t snd_pcm_lib_read1(struct snd_pcm_substream *substream,
              __draining:
                avail = snd_pcm_capture_avail(runtime);
                if (runtime->status->state == SNDRV_PCM_STATE_DRAINING) {
-                       if (avail < runtime->xfer_align) {
+                       if (!avail) {
                                err = -EPIPE;
                                goto _end_unlock;
                        }
-               } else if ((avail < runtime->control->avail_min && size > avail) ||
-                          (size >= runtime->xfer_align && avail < runtime->xfer_align)) {
+               } else if (avail < runtime->control->avail_min &&
+                          size > avail) {
                        wait_queue_t wait;
                        enum { READY, SIGNALED, ERROR, SUSPENDED, EXPIRED, DROPPED } state;
                        long tout;
@@ -2014,8 +2006,6 @@ static snd_pcm_sframes_t snd_pcm_lib_read1(struct snd_pcm_substream *substream,
                                break;
                        }
                }
-               if (avail > runtime->xfer_align)
-                       avail -= avail % runtime->xfer_align;
                frames = size > avail ? avail : size;
                cont = runtime->buffer_size - runtime->control->appl_ptr % runtime->buffer_size;
                if (frames > cont)

diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c
index 3fc33de..3c22d78 100644 (file)
--- a/sound/core/pcm_native.c
+++ b/sound/core/pcm_native.c
@@ -435,7 +435,6 @@ static int snd_pcm_hw_params(struct snd_pcm_substream *substream,
        runtime->period_step = 1;
        runtime->sleep_min = 0;
        runtime->control->avail_min = runtime->period_size;
-       runtime->xfer_align = runtime->period_size;
        runtime->start_threshold = 1;
        runtime->stop_threshold = runtime->buffer_size;
        runtime->silence_threshold = 0;
@@ -532,9 +531,6 @@ static int snd_pcm_sw_params(struct snd_pcm_substream *substream,
                return -EINVAL;
        if (params->avail_min == 0)
                return -EINVAL;
-       if (params->xfer_align == 0 ||
-           params->xfer_align % runtime->min_align != 0)
-               return -EINVAL;
        if (params->silence_size >= runtime->boundary) {
                if (params->silence_threshold != 0)
                        return -EINVAL;
@@ -553,7 +549,6 @@ static int snd_pcm_sw_params(struct snd_pcm_substream *substream,
        runtime->stop_threshold = params->stop_threshold;
        runtime->silence_threshold = params->silence_threshold;
        runtime->silence_size = params->silence_size;
-       runtime->xfer_align = params->xfer_align;
         params->boundary = runtime->boundary;
        if (snd_pcm_running(substream)) {
                if (runtime->sleep_min)
@@ -2239,8 +2234,6 @@ static snd_pcm_sframes_t snd_pcm_playback_rewind(struct snd_pcm_substream *subst
        }
        if (frames > (snd_pcm_uframes_t)hw_avail)
                frames = hw_avail;
-       else
-               frames -= frames % runtime->xfer_align;
        appl_ptr = runtime->control->appl_ptr - frames;
        if (appl_ptr < 0)
                appl_ptr += runtime->boundary;
@@ -2289,8 +2282,6 @@ static snd_pcm_sframes_t snd_pcm_capture_rewind(struct snd_pcm_substream *substr
        }
        if (frames > (snd_pcm_uframes_t)hw_avail)
                frames = hw_avail;
-       else
-               frames -= frames % runtime->xfer_align;
        appl_ptr = runtime->control->appl_ptr - frames;
        if (appl_ptr < 0)
                appl_ptr += runtime->boundary;
@@ -2340,8 +2331,6 @@ static snd_pcm_sframes_t snd_pcm_playback_forward(struct snd_pcm_substream *subs
        }
        if (frames > (snd_pcm_uframes_t)avail)
                frames = avail;
-       else
-               frames -= frames % runtime->xfer_align;
        appl_ptr = runtime->control->appl_ptr + frames;
        if (appl_ptr >= (snd_pcm_sframes_t)runtime->boundary)
                appl_ptr -= runtime->boundary;
@@ -2391,8 +2380,6 @@ static snd_pcm_sframes_t snd_pcm_capture_forward(struct snd_pcm_substream *subst
        }
        if (frames > (snd_pcm_uframes_t)avail)
                frames = avail;
-       else
-               frames -= frames % runtime->xfer_align;
        appl_ptr = runtime->control->appl_ptr + frames;
        if (appl_ptr >= (snd_pcm_sframes_t)runtime->boundary)
                appl_ptr -= runtime->boundary;