merge glitch-free branch back into trunk

git-svn-id: file:///home/lennart/svn/public/pulseaudio/trunk@2445 fefdeb5f-60dc-0310-8127-8f9354f1896f

1 files changed, 800 insertions, 279 deletions

diff --git a/src/modules/module-alsa-sink.c b/src/modules/module-alsa-sink.c
index 14aef7c9..95a72fdc 100644
--- a/src/modules/module-alsa-sink.c
+++ b/src/modules/module-alsa-sink.c
@@ -3,7 +3,7 @@
 /***
   This file is part of PulseAudio.
 
-  Copyright 2004-2006 Lennart Poettering
+  Copyright 2004-2008 Lennart Poettering
   Copyright 2006 Pierre Ossman <ossman@cendio.se> for Cendio AB
 
   PulseAudio is free software; you can redistribute it and/or modify
@@ -32,6 +32,7 @@
 
 #include <pulse/xmalloc.h>
 #include <pulse/util.h>
+#include <pulse/timeval.h>
 
 #include <pulsecore/core.h>
 #include <pulsecore/module.h>
@@ -46,6 +47,8 @@
 #include <pulsecore/core-error.h>
 #include <pulsecore/thread-mq.h>
 #include <pulsecore/rtpoll.h>
+#include <pulsecore/rtclock.h>
+#include <pulsecore/time-smoother.h>
 
 #include "alsa-util.h"
 #include "module-alsa-sink-symdef.h"
@@ -57,16 +60,42 @@ PA_MODULE_LOAD_ONCE(FALSE);
 PA_MODULE_USAGE(
         "sink_name=<name for the sink> "
         "device=<ALSA device> "
-        "device_id=<ALSA device id> "
+        "device_id=<ALSA card index> "
         "format=<sample format> "
-        "channels=<number of channels> "
         "rate=<sample rate> "
+        "channels=<number of channels> "
+        "channel_map=<channel map> "
         "fragments=<number of fragments> "
         "fragment_size=<fragment size> "
-        "channel_map=<channel map> "
-        "mmap=<enable memory mapping?>");
+        "mmap=<enable memory mapping?> "
+        "tsched=<enable system timer based scheduling mode?> "
+        "tsched_buffer_size=<buffer size when using timer based scheduling> "
+        "tsched_buffer_watermark=<lower fill watermark> "
+        "mixer_reset=<reset hw volume and mute settings to sane defaults when falling back to software?>");
+
+static const char* const valid_modargs[] = {
+    "sink_name",
+    "device",
+    "device_id",
+    "format",
+    "rate",
+    "channels",
+    "channel_map",
+    "fragments",
+    "fragment_size",
+    "mmap",
+    "tsched",
+    "tsched_buffer_size",
+    "tsched_buffer_watermark",
+    "mixer_reset",
+    NULL
+};
 
 #define DEFAULT_DEVICE "default"
+#define DEFAULT_TSCHED_BUFFER_USEC (2*PA_USEC_PER_SEC)            /* 2s */
+#define DEFAULT_TSCHED_WATERMARK_USEC (20*PA_USEC_PER_MSEC)       /* 20ms */
+#define TSCHED_MIN_SLEEP_USEC (3*PA_USEC_PER_MSEC)                /* 3ms */
+#define TSCHED_MIN_WAKEUP_USEC (3*PA_USEC_PER_MSEC)               /* 3ms */
 
 struct userdata {
     pa_core *core;
@@ -83,227 +112,404 @@ struct userdata {
     snd_mixer_t *mixer_handle;
     snd_mixer_elem_t *mixer_elem;
     long hw_volume_max, hw_volume_min;
+    long hw_dB_max, hw_dB_min;
+    pa_bool_t hw_dB_supported;
 
-    size_t frame_size, fragment_size, hwbuf_size;
+    size_t frame_size, fragment_size, hwbuf_size, tsched_watermark;
     unsigned nfragments;
     pa_memchunk memchunk;
 
     char *device_name;
 
-    pa_bool_t use_mmap;
+    pa_bool_t use_mmap, use_tsched;
 
-    pa_bool_t first;
+    pa_bool_t first, after_rewind;
 
     pa_rtpoll_item *alsa_rtpoll_item;
 
     snd_mixer_selem_channel_id_t mixer_map[SND_MIXER_SCHN_LAST];
-};
 
-static const char* const valid_modargs[] = {
-    "device",
-    "device_id",
-    "sink_name",
-    "format",
-    "channels",
-    "rate",
-    "fragments",
-    "fragment_size",
-    "channel_map",
-    "mmap",
-    NULL
+    pa_smoother *smoother;
+    int64_t frame_index;
+    uint64_t since_start;
+
+    snd_pcm_sframes_t hwbuf_unused_frames;
 };
 
-static int mmap_write(struct userdata *u) {
+static void fix_tsched_watermark(struct userdata *u) {
+    size_t max_use;
+    size_t min_sleep, min_wakeup;
+    pa_assert(u);
+
+    max_use = u->hwbuf_size - u->hwbuf_unused_frames * u->frame_size;
+
+    min_sleep = pa_usec_to_bytes(TSCHED_MIN_SLEEP_USEC, &u->sink->sample_spec);
+    min_wakeup = pa_usec_to_bytes(TSCHED_MIN_WAKEUP_USEC, &u->sink->sample_spec);
+
+    if (min_sleep > max_use/2)
+        min_sleep = pa_frame_align(max_use/2, &u->sink->sample_spec);
+    if (min_sleep < u->frame_size)
+        min_sleep = u->frame_size;
+
+    if (min_wakeup > max_use/2)
+        min_wakeup = pa_frame_align(max_use/2, &u->sink->sample_spec);
+    if (min_wakeup < u->frame_size)
+        min_wakeup = u->frame_size;
+
+    if (u->tsched_watermark > max_use-min_sleep)
+        u->tsched_watermark = max_use-min_sleep;
+
+    if (u->tsched_watermark < min_wakeup)
+        u->tsched_watermark = min_wakeup;
+}
+
+static void hw_sleep_time(struct userdata *u, pa_usec_t *sleep_usec, pa_usec_t*process_usec) {
+    pa_usec_t usec, wm;
+
+    pa_assert(sleep_usec);
+    pa_assert(process_usec);
+
+    pa_assert(u);
+
+    usec = pa_sink_get_requested_latency_within_thread(u->sink);
+
+    if (usec == (pa_usec_t) -1)
+        usec = pa_bytes_to_usec(u->hwbuf_size, &u->sink->sample_spec);
+
+/*     pa_log_debug("hw buffer time: %u ms", (unsigned) (usec / PA_USEC_PER_MSEC)); */
+
+    wm = pa_bytes_to_usec(u->tsched_watermark, &u->sink->sample_spec);
+
+    if (usec >= wm) {
+        *sleep_usec = usec - wm;
+        *process_usec = wm;
+    } else
+        *process_usec = *sleep_usec = usec / 2;
+
+/*     pa_log_debug("after watermark: %u ms", (unsigned) (*sleep_usec / PA_USEC_PER_MSEC)); */
+}
+
+static int try_recover(struct userdata *u, const char *call, int err) {
+    pa_assert(u);
+    pa_assert(call);
+    pa_assert(err < 0);
+
+    pa_log_debug("%s: %s", call, snd_strerror(err));
+
+    pa_assert(err != -EAGAIN);
+
+    if (err == -EPIPE)
+        pa_log_debug("%s: Buffer underrun!", call);
+
+    if ((err = snd_pcm_recover(u->pcm_handle, err, 1)) == 0) {
+        u->first = TRUE;
+        u->since_start = 0;
+        return 0;
+    }
+
+    pa_log("%s: %s", call, snd_strerror(err));
+    return -1;
+}
+
+static size_t check_left_to_play(struct userdata *u, snd_pcm_sframes_t n) {
+    size_t left_to_play;
+
+    if (n*u->frame_size < u->hwbuf_size)
+        left_to_play = u->hwbuf_size - (n*u->frame_size);
+    else
+        left_to_play = 0;
+
+    if (left_to_play > 0) {
+/*         pa_log_debug("%0.2f ms left to play", (double) pa_bytes_to_usec(left_to_play, &u->sink->sample_spec) / PA_USEC_PER_MSEC); */
+    } else if (!u->first && !u->after_rewind) {
+        pa_log_info("Underrun!");
+
+        if (u->use_tsched) {
+            size_t old_watermark = u->tsched_watermark;
+
+            u->tsched_watermark *= 2;
+            fix_tsched_watermark(u);
+
+            if (old_watermark != u->tsched_watermark)
+                pa_log_notice("Increasing wakeup watermark to %0.2f ms",
+                              (double) pa_bytes_to_usec(u->tsched_watermark, &u->sink->sample_spec) / PA_USEC_PER_MSEC);
+        }
+    }
+
+    return left_to_play;
+}
+
+static int mmap_write(struct userdata *u, pa_usec_t *sleep_usec) {
     int work_done = 0;
+    pa_usec_t max_sleep_usec, process_usec;
+    size_t left_to_play;
 
     pa_assert(u);
     pa_sink_assert_ref(u->sink);
 
+    if (u->use_tsched)
+        hw_sleep_time(u, &max_sleep_usec, &process_usec);
+
     for (;;) {
-        pa_memchunk chunk;
-        void *p;
         snd_pcm_sframes_t n;
-        int err;
-        const snd_pcm_channel_area_t *areas;
-        snd_pcm_uframes_t offset, frames;
+        int r;
 
-        if ((n = snd_pcm_avail_update(u->pcm_handle)) < 0) {
+        snd_pcm_hwsync(u->pcm_handle);
 
-            if (n == -EPIPE) {
-                pa_log_debug("snd_pcm_avail_update: Buffer underrun!");
-                u->first = TRUE;
-            }
+        /* First we determine how many samples are missing to fill the
+         * buffer up to 100% */
 
-            if ((err = snd_pcm_recover(u->pcm_handle, n, 1)) == 0)
-                continue;
+        if (PA_UNLIKELY((n = snd_pcm_avail_update(u->pcm_handle)) < 0)) {
 
-            if (err == -EAGAIN)
-                return work_done;
+            if ((r = try_recover(u, "snd_pcm_avail_update", n)) == 0)
+                continue;
 
-            pa_log("snd_pcm_avail_update: %s", snd_strerror(err));
-            return -1;
+            return r;
         }
 
-/*         pa_log("Got request for %i samples", (int) n); */
+        left_to_play = check_left_to_play(u, n);
 
-        if (n <= 0)
-            return work_done;
+        if (u->use_tsched)
 
-        frames = n;
+            /* We won't fill up the playback buffer before at least
+            * half the sleep time is over because otherwise we might
+            * ask for more data from the clients then they expect. We
+            * need to guarantee that clients only have to keep around
+            * a single hw buffer length. */
 
-        if ((err = snd_pcm_mmap_begin(u->pcm_handle, &areas, &offset, &frames)) < 0) {
+            if (pa_bytes_to_usec(left_to_play, &u->sink->sample_spec) > max_sleep_usec/2)
+                break;
 
-            if (err == -EPIPE) {
-                pa_log_debug("snd_pcm_mmap_begin: Buffer underrun!");
-                u->first = TRUE;
-            }
+        if (PA_UNLIKELY(n <= u->hwbuf_unused_frames))
+            break;
 
-            if ((err = snd_pcm_recover(u->pcm_handle, err, 1)) == 0)
-                continue;
+        n -= u->hwbuf_unused_frames;
 
-            if (err == -EAGAIN)
-                return work_done;
+/*         pa_log_debug("Filling up"); */
 
-            pa_log("Failed to write data to DSP: %s", snd_strerror(err));
-            return -1;
-        }
+        for (;;) {
+            pa_memchunk chunk;
+            void *p;
+            int err;
+            const snd_pcm_channel_area_t *areas;
+            snd_pcm_uframes_t offset, frames = (snd_pcm_uframes_t) n;
 
-        /* Check these are multiples of 8 bit */
-        pa_assert((areas[0].first & 7) == 0);
-        pa_assert((areas[0].step & 7)== 0);
+/*             pa_log_debug("%lu frames to write", (unsigned long) frames); */
 
-        /* We assume a single interleaved memory buffer */
-        pa_assert((areas[0].first >> 3) == 0);
-        pa_assert((areas[0].step >> 3) == u->frame_size);
+            if (PA_UNLIKELY((err = snd_pcm_mmap_begin(u->pcm_handle, &areas, &offset, &frames)) < 0)) {
 
-        p = (uint8_t*) areas[0].addr + (offset * u->frame_size);
+                if ((r = try_recover(u, "snd_pcm_mmap_begin", err)) == 0)
+                    continue;
 
-        chunk.memblock = pa_memblock_new_fixed(u->core->mempool, p, frames * u->frame_size, 1);
-        chunk.length = pa_memblock_get_length(chunk.memblock);
-        chunk.index = 0;
+                return r;
+            }
 
-        pa_sink_render_into_full(u->sink, &chunk);
+            /* Make sure that if these memblocks need to be copied they will fit into one slot */
+            if (frames > pa_mempool_block_size_max(u->sink->core->mempool)/u->frame_size)
+                frames = pa_mempool_block_size_max(u->sink->core->mempool)/u->frame_size;
 
-        /* FIXME: Maybe we can do something to keep this memory block
-         * a little bit longer around? */
-        pa_memblock_unref_fixed(chunk.memblock);
+            /* Check these are multiples of 8 bit */
+            pa_assert((areas[0].first & 7) == 0);
+            pa_assert((areas[0].step & 7)== 0);
 
-        if ((err = snd_pcm_mmap_commit(u->pcm_handle, offset, frames)) < 0) {
+            /* We assume a single interleaved memory buffer */
+            pa_assert((areas[0].first >> 3) == 0);
+            pa_assert((areas[0].step >> 3) == u->frame_size);
 
-            if (err == -EPIPE) {
-                pa_log_debug("snd_pcm_mmap_commit: Buffer underrun!");
-                u->first = TRUE;
-            }
+            p = (uint8_t*) areas[0].addr + (offset * u->frame_size);
 
-            if ((err = snd_pcm_recover(u->pcm_handle, err, 1)) == 0)
-                continue;
+            chunk.memblock = pa_memblock_new_fixed(u->core->mempool, p, frames * u->frame_size, TRUE);
+            chunk.length = pa_memblock_get_length(chunk.memblock);
+            chunk.index = 0;
 
-            if (err == -EAGAIN)
-                return work_done;
+            pa_sink_render_into_full(u->sink, &chunk);
 
-            pa_log("Failed to write data to DSP: %s", snd_strerror(err));
-            return -1;
-        }
+            /* FIXME: Maybe we can do something to keep this memory block
+             * a little bit longer around? */
+            pa_memblock_unref_fixed(chunk.memblock);
 
-        work_done = 1;
+            if (PA_UNLIKELY((err = snd_pcm_mmap_commit(u->pcm_handle, offset, frames)) < 0)) {
 
-        if (frames >= (snd_pcm_uframes_t) n)
-            return work_done;
+                if ((r = try_recover(u, "snd_pcm_mmap_commit", err)) == 0)
+                    continue;
 
-/*         pa_log("wrote %i samples", (int) frames); */
+                return r;
+            }
+
+            work_done = 1;
+
+            u->frame_index += frames;
+            u->since_start += frames * u->frame_size;
+
+/*             pa_log_debug("wrote %lu frames", (unsigned long) frames); */
+
+            if (frames >= (snd_pcm_uframes_t) n)
+                break;
+
+            n -= frames;
+        }
     }
+
+    *sleep_usec = pa_bytes_to_usec(left_to_play, &u->sink->sample_spec) - process_usec;
+    return work_done;
 }
 
-static int unix_write(struct userdata *u) {
-    snd_pcm_status_t *status;
+static int unix_write(struct userdata *u, pa_usec_t *sleep_usec) {
     int work_done = 0;
-
-    snd_pcm_status_alloca(&status);
+    pa_usec_t max_sleep_usec, process_usec;
+    size_t left_to_play;
 
     pa_assert(u);
     pa_sink_assert_ref(u->sink);
 
+    if (u->use_tsched)
+        hw_sleep_time(u, &max_sleep_usec, &process_usec);
+
     for (;;) {
-        void *p;
-        snd_pcm_sframes_t t;
-        ssize_t l;
-        int err;
+        snd_pcm_sframes_t n;
+        int r;
 
-        if ((err = snd_pcm_status(u->pcm_handle, status)) < 0) {
-            pa_log("Failed to query DSP status data: %s", snd_strerror(err));
-            return -1;
+        snd_pcm_hwsync(u->pcm_handle);
+
+        if (PA_UNLIKELY((n = snd_pcm_avail_update(u->pcm_handle)) < 0)) {
+
+            if ((r = try_recover(u, "snd_pcm_avail_update", n)) == 0)
+                continue;
+
+            return r;
         }
 
-        if (snd_pcm_status_get_avail_max(status)*u->frame_size >= u->hwbuf_size)
-            pa_log_debug("Buffer underrun!");
+        left_to_play = check_left_to_play(u, n);
 
-        l = snd_pcm_status_get_avail(status) * u->frame_size;
+        if (u->use_tsched)
 
-/*         pa_log("%u bytes to write", l); */
+            /* We won't fill up the playback buffer before at least
+            * half the sleep time is over because otherwise we might
+            * ask for more data from the clients then they expect. We
+            * need to guarantee that clients only have to keep around
+            * a single hw buffer length. */
 
-        if (l <= 0)
-            return work_done;
+            if (pa_bytes_to_usec(left_to_play, &u->sink->sample_spec) > max_sleep_usec/2)
+                break;
 
-        if (u->memchunk.length <= 0)
-            pa_sink_render(u->sink, l, &u->memchunk);
+        if (PA_UNLIKELY(n <= u->hwbuf_unused_frames))
+            break;
 
-        pa_assert(u->memchunk.length > 0);
+        n -= u->hwbuf_unused_frames;
 
-        p = pa_memblock_acquire(u->memchunk.memblock);
-        t = snd_pcm_writei(u->pcm_handle, (const uint8_t*) p + u->memchunk.index, u->memchunk.length / u->frame_size);
-        pa_memblock_release(u->memchunk.memblock);
+        for (;;) {
+            snd_pcm_sframes_t frames;
+            void *p;
 
-/*         pa_log("wrote %i bytes of %u (%u)", t*u->frame_size, u->memchunk.length, l); */
+/*         pa_log_debug("%lu frames to write", (unsigned long) frames); */
 
-        pa_assert(t != 0);
+            if (u->memchunk.length <= 0)
+                pa_sink_render(u->sink, n * u->frame_size, &u->memchunk);
 
-        if (t < 0) {
+            pa_assert(u->memchunk.length > 0);
 
-            if ((t = snd_pcm_recover(u->pcm_handle, t, 1)) == 0)
-                continue;
+            frames = u->memchunk.length / u->frame_size;
+
+            if (frames > n)
+                frames = n;
+
+            p = pa_memblock_acquire(u->memchunk.memblock);
+            frames = snd_pcm_writei(u->pcm_handle, (const uint8_t*) p + u->memchunk.index, frames);
+            pa_memblock_release(u->memchunk.memblock);
 
-            if (t == -EAGAIN) {
-                pa_log_debug("EAGAIN");
-                return work_done;
-            } else {
-                pa_log("Failed to write data to DSP: %s", snd_strerror(t));
-                return -1;
+            pa_assert(frames != 0);
+
+            if (PA_UNLIKELY(frames < 0)) {
+
+                if ((r = try_recover(u, "snd_pcm_writei", n)) == 0)
+                    continue;
+
+                return r;
             }
-        }
 
-        u->memchunk.index += t * u->frame_size;
-        u->memchunk.length -= t * u->frame_size;
+            u->memchunk.index += frames * u->frame_size;
+            u->memchunk.length -= frames * u->frame_size;
 
-        if (u->memchunk.length <= 0) {
-            pa_memblock_unref(u->memchunk.memblock);
-            pa_memchunk_reset(&u->memchunk);
-        }
+            if (u->memchunk.length <= 0) {
+                pa_memblock_unref(u->memchunk.memblock);
+                pa_memchunk_reset(&u->memchunk);
+            }
+
+            work_done = 1;
+
+            u->frame_index += frames;
+            u->since_start += frames * u->frame_size;
 
-        work_done = 1;
+/*         pa_log_debug("wrote %lu frames", (unsigned long) frames); */
 
-        if (t * u->frame_size >= (unsigned) l)
-            return work_done;
+            if (frames >= n)
+                break;
+
+            n -= frames;
+        }
     }
+
+    *sleep_usec = pa_bytes_to_usec(left_to_play, &u->sink->sample_spec) - process_usec;
+    return work_done;
 }
 
-static pa_usec_t sink_get_latency(struct userdata *u) {
-    pa_usec_t r = 0;
-    snd_pcm_status_t *status;
-    snd_pcm_sframes_t frames = 0;
+static void update_smoother(struct userdata *u) {
+    snd_pcm_sframes_t delay  = 0;
+    int64_t frames;
     int err;
+    pa_usec_t now1, now2;
+/*     struct timeval timestamp; */
+    snd_pcm_status_t *status;
 
     snd_pcm_status_alloca(&status);
 
     pa_assert(u);
     pa_assert(u->pcm_handle);
 
-    if ((err = snd_pcm_status(u->pcm_handle, status)) < 0)
-        pa_log("Failed to get delay: %s", snd_strerror(err));
-    else
-        frames = snd_pcm_status_get_delay(status);
+    /* Let's update the time smoother */
+
+    snd_pcm_hwsync(u->pcm_handle);
+    snd_pcm_avail_update(u->pcm_handle);
+
+/*     if (PA_UNLIKELY((err = snd_pcm_status(u->pcm_handle, status)) < 0)) { */
+/*         pa_log("Failed to query DSP status data: %s", snd_strerror(err)); */
+/*         return; */
+/*     } */
+
+/*     delay = snd_pcm_status_get_delay(status); */
+
+    if (PA_UNLIKELY((err = snd_pcm_delay(u->pcm_handle, &delay)) < 0)) {
+        pa_log("Failed to query DSP status data: %s", snd_strerror(err));
+        return;
+    }
+
+    frames = u->frame_index - delay;
+
+/*     pa_log_debug("frame_index = %llu, delay = %llu, p = %llu", (unsigned long long) u->frame_index, (unsigned long long) delay, (unsigned long long) frames); */
+
+/*     snd_pcm_status_get_tstamp(status, &timestamp); */
+/*     pa_rtclock_from_wallclock(&timestamp); */
+/*     now1 = pa_timeval_load(&timestamp); */
+
+    now1 = pa_rtclock_usec();
+    now2 = pa_bytes_to_usec(frames * u->frame_size, &u->sink->sample_spec);
+    pa_smoother_put(u->smoother, now1, now2);
+}
+
+static pa_usec_t sink_get_latency(struct userdata *u) {
+    pa_usec_t r = 0;
+    int64_t delay;
+    pa_usec_t now1, now2;
+
+    pa_assert(u);
+
+    now1 = pa_rtclock_usec();
+    now2 = pa_smoother_get(u->smoother, now1);
+
+    delay = (int64_t) pa_bytes_to_usec(u->frame_index * u->frame_size, &u->sink->sample_spec) - (int64_t) now2;
 
-    if (frames > 0)
-        r = pa_bytes_to_usec(frames * u->frame_size, &u->sink->sample_spec);
+    if (delay > 0)
+        r = (pa_usec_t) delay;
 
     if (u->memchunk.memblock)
         r += pa_bytes_to_usec(u->memchunk.length, &u->sink->sample_spec);
@@ -312,28 +518,14 @@ static pa_usec_t sink_get_latency(struct userdata *u) {
 }
 
 static int build_pollfd(struct userdata *u) {
-    int err;
-    struct pollfd *pollfd;
-    int n;
-
     pa_assert(u);
     pa_assert(u->pcm_handle);
 
-    if ((n = snd_pcm_poll_descriptors_count(u->pcm_handle)) < 0) {
-        pa_log("snd_pcm_poll_descriptors_count() failed: %s", snd_strerror(n));
-        return -1;
-    }
-
     if (u->alsa_rtpoll_item)
         pa_rtpoll_item_free(u->alsa_rtpoll_item);
 
-    u->alsa_rtpoll_item = pa_rtpoll_item_new(u->rtpoll, PA_RTPOLL_NEVER, n);
-    pollfd = pa_rtpoll_item_get_pollfd(u->alsa_rtpoll_item, NULL);
-
-    if ((err = snd_pcm_poll_descriptors(u->pcm_handle, pollfd, n)) < 0) {
-        pa_log("snd_pcm_poll_descriptors() failed: %s", snd_strerror(err));
+    if (!(u->alsa_rtpoll_item = pa_alsa_build_pollfd(u->pcm_handle, u->rtpoll)))
         return -1;
-    }
 
     return 0;
 }
@@ -342,6 +534,8 @@ static int suspend(struct userdata *u) {
     pa_assert(u);
     pa_assert(u->pcm_handle);
 
+    pa_smoother_pause(u->smoother, pa_rtclock_usec());
+
     /* Let's suspend */
     snd_pcm_drain(u->pcm_handle);
     snd_pcm_close(u->pcm_handle);
@@ -357,10 +551,64 @@ static int suspend(struct userdata *u) {
     return 0;
 }
 
+static int update_sw_params(struct userdata *u) {
+    snd_pcm_uframes_t avail_min;
+    int err;
+
+    pa_assert(u);
+
+    /* Use the full buffer if noone asked us for anything specific */
+    u->hwbuf_unused_frames = 0;
+
+    if (u->use_tsched) {
+        pa_usec_t latency;
+
+        if ((latency = pa_sink_get_requested_latency_within_thread(u->sink)) != (pa_usec_t) -1) {
+            size_t b;
+
+            pa_log_debug("latency set to %0.2f", (double) latency / PA_USEC_PER_MSEC);
+
+            b = pa_usec_to_bytes(latency, &u->sink->sample_spec);
+
+            /* We need at least one sample in our buffer */
+
+            if (PA_UNLIKELY(b < u->frame_size))
+                b = u->frame_size;
+
+            u->hwbuf_unused_frames =
+                PA_LIKELY(b < u->hwbuf_size) ?
+                ((u->hwbuf_size - b) / u->frame_size) : 0;
+
+            fix_tsched_watermark(u);
+        }
+    }
+
+    pa_log_debug("hwbuf_unused_frames=%lu", (unsigned long) u->hwbuf_unused_frames);
+
+    /* We need at last one frame in the used part of the buffer */
+    avail_min = u->hwbuf_unused_frames + 1;
+
+    if (u->use_tsched) {
+        pa_usec_t sleep_usec, process_usec;
+
+        hw_sleep_time(u, &sleep_usec, &process_usec);
+        avail_min += pa_usec_to_bytes(sleep_usec, &u->sink->sample_spec);
+    }
+
+    pa_log_debug("setting avail_min=%lu", (unsigned long) avail_min);
+
+    if ((err = pa_alsa_set_sw_params(u->pcm_handle, avail_min)) < 0) {
+        pa_log("Failed to set software parameters: %s", snd_strerror(err));
+        return err;
+    }
+
+    return 0;
+}
+
 static int unsuspend(struct userdata *u) {
     pa_sample_spec ss;
     int err;
-    pa_bool_t b;
+    pa_bool_t b, d;
     unsigned nfrags;
     snd_pcm_uframes_t period_size;
 
@@ -379,13 +627,14 @@ static int unsuspend(struct userdata *u) {
     nfrags = u->nfragments;
     period_size = u->fragment_size / u->frame_size;
     b = u->use_mmap;
+    d = u->use_tsched;
 
-    if ((err = pa_alsa_set_hw_params(u->pcm_handle, &ss, &nfrags, &period_size, &b, TRUE)) < 0) {
+    if ((err = pa_alsa_set_hw_params(u->pcm_handle, &ss, &nfrags, &period_size, u->hwbuf_size / u->frame_size, &b, &d, TRUE)) < 0) {
         pa_log("Failed to set hardware parameters: %s", snd_strerror(err));
         goto fail;
     }
 
-    if (b != u->use_mmap) {
+    if (b != u->use_mmap || d != u->use_tsched) {
         pa_log_warn("Resume failed, couldn't get original access mode.");
         goto fail;
     }
@@ -400,10 +649,8 @@ static int unsuspend(struct userdata *u) {
         goto fail;
     }
 
-    if ((err = pa_alsa_set_sw_params(u->pcm_handle)) < 0) {
-        pa_log("Failed to set software parameters: %s", snd_strerror(err));
+    if (update_sw_params(u) < 0)
         goto fail;
-    }
 
     if (build_pollfd(u) < 0)
         goto fail;
@@ -411,6 +658,7 @@ static int unsuspend(struct userdata *u) {
     /* FIXME: We need to reload the volume somehow */
 
     u->first = TRUE;
+    u->since_start = 0;
 
     pa_log_info("Resumed successfully...");
 
@@ -446,7 +694,7 @@ static int sink_process_msg(pa_msgobject *o, int code, void *data, int64_t offse
             switch ((pa_sink_state_t) PA_PTR_TO_UINT(data)) {
 
                 case PA_SINK_SUSPENDED:
-                    pa_assert(PA_SINK_OPENED(u->sink->thread_info.state));
+                    pa_assert(PA_SINK_IS_OPENED(u->sink->thread_info.state));
 
                     if (suspend(u) < 0)
                         return -1;
@@ -505,18 +753,24 @@ static int sink_get_volume_cb(pa_sink *s) {
     pa_assert(u->mixer_elem);
 
     for (i = 0; i < s->sample_spec.channels; i++) {
-        long set_vol, vol;
+        long alsa_vol;
 
         pa_assert(snd_mixer_selem_has_playback_channel(u->mixer_elem, u->mixer_map[i]));
 
-        if ((err = snd_mixer_selem_get_playback_volume(u->mixer_elem, u->mixer_map[i], &vol)) < 0)
-            goto fail;
+        if (u->hw_dB_supported) {
 
-        set_vol = (long) roundf(((float) s->volume.values[i] * (u->hw_volume_max - u->hw_volume_min)) / PA_VOLUME_NORM) + u->hw_volume_min;
+            if ((err = snd_mixer_selem_get_playback_dB(u->mixer_elem, u->mixer_map[i], &alsa_vol)) >= 0) {
+                s->volume.values[i] = pa_sw_volume_from_dB(alsa_vol / 100.0);
+                continue;
+            }
+
+            u->hw_dB_supported = FALSE;
+        }
+
+        if ((err = snd_mixer_selem_get_playback_volume(u->mixer_elem, u->mixer_map[i], &alsa_vol)) < 0)
+            goto fail;
 
-        /* Try to avoid superfluous volume changes */
-        if (set_vol != vol)
-            s->volume.values[i] = (pa_volume_t) roundf(((float) (vol - u->hw_volume_min) * PA_VOLUME_NORM) / (u->hw_volume_max - u->hw_volume_min));
+        s->volume.values[i] = (pa_volume_t) roundf(((float) (alsa_vol - u->hw_volume_min) * PA_VOLUME_NORM) / (u->hw_volume_max - u->hw_volume_min));
     }
 
     return 0;
@@ -524,8 +778,6 @@ static int sink_get_volume_cb(pa_sink *s) {
 fail:
     pa_log_error("Unable to read volume: %s", snd_strerror(err));
 
-    s->get_volume = NULL;
-    s->set_volume = NULL;
     return -1;
 }
 
@@ -543,15 +795,32 @@ static int sink_set_volume_cb(pa_sink *s) {
 
         pa_assert(snd_mixer_selem_has_playback_channel(u->mixer_elem, u->mixer_map[i]));
 
-        vol = s->volume.values[i];
+        vol = PA_MIN(s->volume.values[i], PA_VOLUME_NORM);
 
-        if (vol > PA_VOLUME_NORM)
-            vol = PA_VOLUME_NORM;
+        if (u->hw_dB_supported) {
+            alsa_vol = (long) (pa_sw_volume_to_dB(vol) * 100);
+            alsa_vol = PA_CLAMP_UNLIKELY(alsa_vol, u->hw_dB_min, u->hw_dB_max);
+
+            if ((err = snd_mixer_selem_set_playback_dB(u->mixer_elem, u->mixer_map[i], alsa_vol, -1)) >= 0) {
+
+                if (snd_mixer_selem_get_playback_dB(u->mixer_elem, u->mixer_map[i], &alsa_vol) >= 0)
+                    s->volume.values[i] = pa_sw_volume_from_dB(alsa_vol / 100.0);
+
+                continue;
+            }
+
+            u->hw_dB_supported = FALSE;
+
+        }
 
         alsa_vol = (long) roundf(((float) vol * (u->hw_volume_max - u->hw_volume_min)) / PA_VOLUME_NORM) + u->hw_volume_min;
+        alsa_vol = PA_CLAMP_UNLIKELY(alsa_vol, u->hw_volume_min, u->hw_volume_max);
 
         if ((err = snd_mixer_selem_set_playback_volume(u->mixer_elem, u->mixer_map[i], alsa_vol)) < 0)
             goto fail;
+
+        if (snd_mixer_selem_get_playback_volume(u->mixer_elem, u->mixer_map[i], &alsa_vol) >= 0)
+            s->volume.values[i] = (pa_volume_t) roundf(((float) (alsa_vol - u->hw_volume_min) * PA_VOLUME_NORM) / (u->hw_volume_max - u->hw_volume_min));
     }
 
     return 0;
@@ -559,8 +828,6 @@ static int sink_set_volume_cb(pa_sink *s) {
 fail:
     pa_log_error("Unable to set volume: %s", snd_strerror(err));
 
-    s->get_volume = NULL;
-    s->set_volume = NULL;
     return -1;
 }
 
@@ -573,9 +840,6 @@ static int sink_get_mute_cb(pa_sink *s) {
 
     if ((err = snd_mixer_selem_get_playback_switch(u->mixer_elem, 0, &sw)) < 0) {
         pa_log_error("Unable to get switch: %s", snd_strerror(err));
-
-        s->get_mute = NULL;
-        s->set_mute = NULL;
         return -1;
     }
 
@@ -593,12 +857,90 @@ static int sink_set_mute_cb(pa_sink *s) {
 
     if ((err = snd_mixer_selem_set_playback_switch_all(u->mixer_elem, !s->muted)) < 0) {
         pa_log_error("Unable to set switch: %s", snd_strerror(err));
+        return -1;
+    }
+
+    return 0;
+}
 
-        s->get_mute = NULL;
-        s->set_mute = NULL;
+static void sink_update_requested_latency_cb(pa_sink *s) {
+    struct userdata *u = s->userdata;
+    snd_pcm_sframes_t before;
+    pa_assert(u);
+
+    if (!u->pcm_handle)
+        return;
+
+    before = u->hwbuf_unused_frames;
+    update_sw_params(u);
+
+    /* Let's check whether we now use only a smaller part of the
+    buffer then before. If so, we need to make sure that subsequent
+    rewinds are relative to the new maxium fill level and not to the
+    current fill level. Thus, let's do a full rewind once, to clear
+    things up. */
+
+    if (u->hwbuf_unused_frames > before) {
+        pa_log_debug("Requesting rewind due to latency change.");
+        pa_sink_request_rewind(s, 0);
+    }
+}
+
+static int process_rewind(struct userdata *u) {
+    snd_pcm_sframes_t unused;
+    size_t rewind_nbytes, unused_nbytes, limit_nbytes;
+    pa_assert(u);
+
+    /* Figure out how much we shall rewind and reset the counter */
+    rewind_nbytes = u->sink->thread_info.rewind_nbytes;
+    u->sink->thread_info.rewind_nbytes = 0;
+
+    pa_assert(rewind_nbytes > 0);
+    pa_log_debug("Requested to rewind %lu bytes.", (unsigned long) rewind_nbytes);
+
+    snd_pcm_hwsync(u->pcm_handle);
+    if ((unused = snd_pcm_avail_update(u->pcm_handle)) < 0) {
+        pa_log("snd_pcm_avail_update() failed: %s", snd_strerror(unused));
         return -1;
     }
 
+    unused_nbytes = u->tsched_watermark + (size_t) unused * u->frame_size;
+
+    if (u->hwbuf_size > unused_nbytes)
+        limit_nbytes = u->hwbuf_size - unused_nbytes;
+    else
+        limit_nbytes = 0;
+
+    if (rewind_nbytes > limit_nbytes)
+        rewind_nbytes = limit_nbytes;
+
+    if (rewind_nbytes > 0) {
+        snd_pcm_sframes_t in_frames, out_frames;
+
+        pa_log_debug("Limited to %lu bytes.", (unsigned long) rewind_nbytes);
+
+        in_frames = (snd_pcm_sframes_t) rewind_nbytes / u->frame_size;
+        pa_log_debug("before: %lu", (unsigned long) in_frames);
+        if ((out_frames = snd_pcm_rewind(u->pcm_handle, in_frames)) < 0) {
+            pa_log("snd_pcm_rewind() failed: %s", snd_strerror(out_frames));
+            return -1;
+        }
+        pa_log_debug("after: %lu", (unsigned long) out_frames);
+
+        rewind_nbytes = out_frames * u->frame_size;
+
+        if (rewind_nbytes <= 0)
+            pa_log_info("Tried rewind, but was apparently not possible.");
+        else {
+            u->frame_index -= out_frames;
+            pa_log_debug("Rewound %lu bytes.", (unsigned long) rewind_nbytes);
+            pa_sink_process_rewind(u->sink, rewind_nbytes);
+
+            u->after_rewind = TRUE;
+        }
+    } else
+        pa_log_debug("Mhmm, actually there is nothing to rewind.");
+
     return 0;
 }
 
@@ -618,25 +960,77 @@ static void thread_func(void *userdata) {
     for (;;) {
         int ret;
 
+/*         pa_log_debug("loop"); */
+
         /* Render some data and write it to the dsp */
-        if (PA_SINK_OPENED(u->sink->thread_info.state)) {
-            int work_done = 0;
+        if (PA_SINK_IS_OPENED(u->sink->thread_info.state)) {
+            int work_done;
+            pa_usec_t sleep_usec;
 
-            if (u->use_mmap) {
-                if ((work_done = mmap_write(u)) < 0)
-                    goto fail;
-            } else {
-                if ((work_done = unix_write(u)) < 0)
+            if (u->sink->thread_info.rewind_nbytes > 0)
+                if (process_rewind(u) < 0)
                     goto fail;
+
+            if (u->use_mmap)
+                work_done = mmap_write(u, &sleep_usec);
+            else
+                work_done = unix_write(u, &sleep_usec);
+
+            if (work_done < 0)
+                goto fail;
+
+/*             pa_log_debug("work_done = %i", work_done); */
+
+            if (work_done) {
+
+                if (u->first) {
+                    pa_log_info("Starting playback.");
+                    snd_pcm_start(u->pcm_handle);
+
+                    pa_smoother_resume(u->smoother, pa_rtclock_usec());
+                }
+
+                update_smoother(u);
             }
 
-            if (work_done && u->first) {
-                pa_log_info("Starting playback.");
-                snd_pcm_start(u->pcm_handle);
-                u->first = FALSE;
-                continue;
+            if (u->use_tsched) {
+                pa_usec_t cusec;
+
+                if (u->since_start <= u->hwbuf_size) {
+
+                    /* USB devices on ALSA seem to hit a buffer
+                     * underrun during the first iterations much
+                     * quicker then we calculate here, probably due to
+                     * the transport latency. To accomodate for that
+                     * we artificially decrease the sleep time until
+                     * we have filled the buffer at least once
+                     * completely.*/
+
+                    /*pa_log_debug("Cutting sleep time for the initial iterations by half.");*/
+                    sleep_usec /= 2;
+                }
+
+                /* OK, the playback buffer is now full, let's
+                 * calculate when to wake up next */
+/*                 pa_log_debug("Waking up in %0.2fms (sound card clock).", (double) sleep_usec / PA_USEC_PER_MSEC); */
+
+                /* Convert from the sound card time domain to the
+                 * system time domain */
+                cusec = pa_smoother_translate(u->smoother, pa_rtclock_usec(), sleep_usec);
+
+/*                 pa_log_debug("Waking up in %0.2fms (system clock).", (double) cusec / PA_USEC_PER_MSEC); */
+
+                /* We don't trust the conversion, so we wake up whatever comes first */
+                pa_rtpoll_set_timer_relative(u->rtpoll, PA_MIN(sleep_usec, cusec));
             }
-        }
+
+            u->first = FALSE;
+            u->after_rewind = FALSE;
+
+        } else if (u->use_tsched)
+
+            /* OK, we're in an invalid state, let's disable our timers */
+            pa_rtpoll_set_timer_disabled(u->rtpoll);
 
         /* Hmm, nothing to do. Let's sleep */
         if ((ret = pa_rtpoll_run(u->rtpoll, 1)) < 0)
@@ -646,7 +1040,7 @@ static void thread_func(void *userdata) {
             goto finish;
 
         /* Tell ALSA about this and process its response */
-        if (PA_SINK_OPENED(u->sink->thread_info.state)) {
+        if (PA_SINK_IS_OPENED(u->sink->thread_info.state)) {
             struct pollfd *pollfd;
             unsigned short revents = 0;
             int err;
@@ -660,43 +1054,15 @@ static void thread_func(void *userdata) {
             }
 
             if (revents & (POLLERR|POLLNVAL|POLLHUP)) {
+                if (pa_alsa_recover_from_poll(u->pcm_handle, revents) < 0)
+                    goto fail;
 
-                if (revents & POLLERR)
-                    pa_log_warn("Got POLLERR from ALSA");
-                if (revents & POLLNVAL)
-                    pa_log_warn("Got POLLNVAL from ALSA");
-                if (revents & POLLHUP)
-                    pa_log_warn("Got POLLHUP from ALSA");
-
-                /* Try to recover from this error */
-
-                switch (snd_pcm_state(u->pcm_handle)) {
-
-                    case SND_PCM_STATE_XRUN:
-                        if ((err = snd_pcm_recover(u->pcm_handle, -EPIPE, 1)) != 0) {
-                            pa_log_warn("Could not recover from POLLERR|POLLNVAL|POLLHUP and XRUN: %s", snd_strerror(err));
-                            goto fail;
-                        }
-                        break;
-
-                    case SND_PCM_STATE_SUSPENDED:
-                        if ((err = snd_pcm_recover(u->pcm_handle, -ESTRPIPE, 1)) != 0) {
-                            pa_log_warn("Could not recover from POLLERR|POLLNVAL|POLLHUP and SUSPENDED: %s", snd_strerror(err));
-                            goto fail;
-                        }
-                        break;
-
-                    default:
-
-                        snd_pcm_drop(u->pcm_handle);
-
-                        if ((err = snd_pcm_prepare(u->pcm_handle)) < 0) {
-                            pa_log_warn("Could not recover from POLLERR|POLLNVAL|POLLHUP with snd_pcm_prepare(): %s", snd_strerror(err));
-                            goto fail;
-                        }
-                        break;
-                }
+                u->first = TRUE;
+                u->since_start = 0;
             }
+
+            if (revents && u->use_tsched)
+                pa_log_debug("Wakeup from ALSA! (%i)", revents);
         }
     }
 
@@ -717,21 +1083,24 @@ int pa__init(pa_module*m) {
     const char *dev_id;
     pa_sample_spec ss;
     pa_channel_map map;
-    uint32_t nfrags, frag_size;
-    snd_pcm_uframes_t period_size;
+    uint32_t nfrags, hwbuf_size, frag_size, tsched_size, tsched_watermark;
+    snd_pcm_uframes_t period_frames, tsched_frames;
     size_t frame_size;
     snd_pcm_info_t *pcm_info = NULL;
     int err;
-    char *t;
     const char *name;
     char *name_buf = NULL;
-    int namereg_fail;
-    pa_bool_t use_mmap = TRUE, b;
+    pa_bool_t namereg_fail;
+    pa_bool_t use_mmap = TRUE, b, use_tsched = TRUE, d, mixer_reset = TRUE;
+    pa_usec_t usec;
+    pa_sink_new_data data;
 
     snd_pcm_info_alloca(&pcm_info);
 
     pa_assert(m);
 
+    pa_alsa_redirect_errors_inc();
+
     if (!(ma = pa_modargs_new(m->argument, valid_modargs))) {
         pa_log("Failed to parse module arguments");
         goto fail;
@@ -746,35 +1115,66 @@ int pa__init(pa_module*m) {
     frame_size = pa_frame_size(&ss);
 
     nfrags = m->core->default_n_fragments;
-    frag_size = pa_usec_to_bytes(m->core->default_fragment_size_msec*1000, &ss);
+    frag_size = pa_usec_to_bytes(m->core->default_fragment_size_msec*PA_USEC_PER_MSEC, &ss);
     if (frag_size <= 0)
         frag_size = frame_size;
+    tsched_size = pa_usec_to_bytes(DEFAULT_TSCHED_BUFFER_USEC, &ss);
+    tsched_watermark = pa_usec_to_bytes(DEFAULT_TSCHED_WATERMARK_USEC, &ss);
 
-    if (pa_modargs_get_value_u32(ma, "fragments", &nfrags) < 0 || pa_modargs_get_value_u32(ma, "fragment_size", &frag_size) < 0) {
+    if (pa_modargs_get_value_u32(ma, "fragments", &nfrags) < 0 ||
+        pa_modargs_get_value_u32(ma, "fragment_size", &frag_size) < 0 ||
+        pa_modargs_get_value_u32(ma, "tsched_buffer_size", &tsched_size) < 0 ||
+        pa_modargs_get_value_u32(ma, "tsched_buffer_watermark", &tsched_watermark) < 0) {
         pa_log("Failed to parse buffer metrics");
         goto fail;
     }
-    period_size = frag_size/frame_size;
+
+    hwbuf_size = frag_size * nfrags;
+    period_frames = frag_size/frame_size;
+    tsched_frames = tsched_size/frame_size;
 
     if (pa_modargs_get_value_boolean(ma, "mmap", &use_mmap) < 0) {
         pa_log("Failed to parse mmap argument.");
         goto fail;
     }
 
+    if (pa_modargs_get_value_boolean(ma, "tsched", &use_tsched) < 0) {
+        pa_log("Failed to parse timer_scheduling argument.");
+        goto fail;
+    }
+
+    if (use_tsched && !pa_rtclock_hrtimer()) {
+        pa_log("Disabling timer-based scheduling because high-resolution timers are not available from the kernel.");
+        use_tsched = FALSE;
+    }
+
+    if (pa_modargs_get_value_boolean(ma, "mixer_reset", &mixer_reset) < 0) {
+        pa_log("Failed to parse mixer_reset argument.");
+        goto fail;
+    }
+
     u = pa_xnew0(struct userdata, 1);
     u->core = m->core;
     u->module = m;
     m->userdata = u;
     u->use_mmap = use_mmap;
+    u->use_tsched = use_tsched;
     u->first = TRUE;
-    pa_thread_mq_init(&u->thread_mq, m->core->mainloop);
+    u->since_start = 0;
+    u->after_rewind = FALSE;
     u->rtpoll = pa_rtpoll_new();
+    pa_thread_mq_init(&u->thread_mq, m->core->mainloop, u->rtpoll);
     u->alsa_rtpoll_item = NULL;
-    pa_rtpoll_item_new_asyncmsgq(u->rtpoll, PA_RTPOLL_EARLY, u->thread_mq.inq);
+
+    u->smoother = pa_smoother_new(DEFAULT_TSCHED_BUFFER_USEC*2, DEFAULT_TSCHED_BUFFER_USEC*2, TRUE, 5);
+    usec = pa_rtclock_usec();
+    pa_smoother_set_time_offset(u->smoother, usec);
+    pa_smoother_pause(u->smoother, usec);
 
     snd_config_update_free_global();
 
     b = use_mmap;
+    d = use_tsched;
 
     if ((dev_id = pa_modargs_get_value(ma, "device_id", NULL))) {
 
@@ -783,8 +1183,8 @@ int pa__init(pa_module*m) {
                       &u->device_name,
                       &ss, &map,
                       SND_PCM_STREAM_PLAYBACK,
-                      &nfrags, &period_size,
-                      &b)))
+                      &nfrags, &period_frames, tsched_frames,
+                      &b, &d)))
 
             goto fail;
 
@@ -795,8 +1195,8 @@ int pa__init(pa_module*m) {
                       &u->device_name,
                       &ss, &map,
                       SND_PCM_STREAM_PLAYBACK,
-                      &nfrags, &period_size,
-                      &b)))
+                      &nfrags, &period_frames, tsched_frames,
+                      &b, &d)))
             goto fail;
 
     }
@@ -806,22 +1206,25 @@ int pa__init(pa_module*m) {
 
     if (use_mmap && !b) {
         pa_log_info("Device doesn't support mmap(), falling back to UNIX read/write mode.");
-        u->use_mmap = use_mmap = b;
+        u->use_mmap = use_mmap = FALSE;
+    }
+
+    if (use_tsched && (!b || !d)) {
+        pa_log_info("Cannot enabled timer-based scheduling, falling back to sound IRQ scheduling.");
+        u->use_tsched = use_tsched = FALSE;
     }
 
     if (u->use_mmap)
         pa_log_info("Successfully enabled mmap() mode.");
 
+    if (u->use_tsched)
+        pa_log_info("Successfully enabled timer-based scheduling mode.");
+
     if ((err = snd_pcm_info(u->pcm_handle, pcm_info)) < 0) {
         pa_log("Error fetching PCM info: %s", snd_strerror(err));
         goto fail;
     }
 
-    if ((err = pa_alsa_set_sw_params(u->pcm_handle)) < 0) {
-        pa_log("Failed to set software parameters: %s", snd_strerror(err));
-        goto fail;
-    }
-
     /* ALSA might tweak the sample spec, so recalculate the frame size */
     frame_size = pa_frame_size(&ss);
 
@@ -833,13 +1236,24 @@ int pa__init(pa_module*m) {
         if (pa_alsa_prepare_mixer(u->mixer_handle, u->device_name) >= 0)
             found = TRUE;
         else {
-            char *md = pa_sprintf_malloc("hw:%s", dev_id);
+            snd_pcm_info_t *info;
+
+            snd_pcm_info_alloca(&info);
 
-            if (strcmp(u->device_name, md))
-                if (pa_alsa_prepare_mixer(u->mixer_handle, md) >= 0)
-                    found = TRUE;
+            if (snd_pcm_info(u->pcm_handle, info) >= 0) {
+                char *md;
+                int card;
 
-            pa_xfree(md);
+                if ((card = snd_pcm_info_get_card(info)) >= 0) {
+
+                    md = pa_sprintf_malloc("hw:%i", card);
+
+                    if (strcmp(u->device_name, md))
+                        if (pa_alsa_prepare_mixer(u->mixer_handle, md) >= 0)
+                            found = TRUE;
+                    pa_xfree(md);
+                }
+            }
         }
 
         if (found)
@@ -853,13 +1267,28 @@ int pa__init(pa_module*m) {
     }
 
     if ((name = pa_modargs_get_value(ma, "sink_name", NULL)))
-        namereg_fail = 1;
+        namereg_fail = TRUE;
     else {
         name = name_buf = pa_sprintf_malloc("alsa_output.%s", u->device_name);
-        namereg_fail = 0;
+        namereg_fail = FALSE;
     }
 
-    u->sink = pa_sink_new(m->core, __FILE__, name, namereg_fail, &ss, &map);
+    pa_sink_new_data_init(&data);
+    data.driver = __FILE__;
+    data.module = m;
+    pa_sink_new_data_set_name(&data, name);
+    data.namereg_fail = namereg_fail;
+    pa_sink_new_data_set_sample_spec(&data, &ss);
+    pa_sink_new_data_set_channel_map(&data, &map);
+
+    pa_alsa_init_proplist(data.proplist, pcm_info);
+    pa_proplist_sets(data.proplist, PA_PROP_DEVICE_STRING, u->device_name);
+    pa_proplist_setf(data.proplist, PA_PROP_DEVICE_BUFFERING_BUFFER_SIZE, "%lu", (unsigned long) (period_frames * frame_size * nfrags));
+    pa_proplist_setf(data.proplist, PA_PROP_DEVICE_BUFFERING_FRAGMENT_SIZE, "%lu", (unsigned long) (period_frames * frame_size));
+    pa_proplist_sets(data.proplist, PA_PROP_DEVICE_ACCESS_MODE, u->use_tsched ? "mmap+timer" : (u->use_mmap ? "mmap" : "serial"));
+
+    u->sink = pa_sink_new(m->core, &data, PA_SINK_HARDWARE|PA_SINK_LATENCY);
+    pa_sink_new_data_done(&data);
     pa_xfree(name_buf);
 
     if (!u->sink) {
@@ -868,26 +1297,41 @@ int pa__init(pa_module*m) {
     }
 
     u->sink->parent.process_msg = sink_process_msg;
+    u->sink->update_requested_latency = sink_update_requested_latency_cb;
     u->sink->userdata = u;
 
-    pa_sink_set_module(u->sink, m);
     pa_sink_set_asyncmsgq(u->sink, u->thread_mq.inq);
     pa_sink_set_rtpoll(u->sink, u->rtpoll);
-    pa_sink_set_description(u->sink, t = pa_sprintf_malloc(
-                                    "ALSA PCM on %s (%s)%s",
-                                    u->device_name,
-                                    snd_pcm_info_get_name(pcm_info),
-                                    use_mmap ? " via DMA" : ""));
-    pa_xfree(t);
-
-    u->sink->flags = PA_SINK_HARDWARE|PA_SINK_LATENCY;
 
     u->frame_size = frame_size;
-    u->fragment_size = frag_size = period_size * frame_size;
+    u->fragment_size = frag_size = period_frames * frame_size;
     u->nfragments = nfrags;
     u->hwbuf_size = u->fragment_size * nfrags;
-
-    pa_log_info("Using %u fragments of size %lu bytes.", nfrags, (long unsigned) u->fragment_size);
+    u->hwbuf_unused_frames = 0;
+    u->tsched_watermark = tsched_watermark;
+    u->frame_index = 0;
+    u->hw_dB_supported = FALSE;
+    u->hw_dB_min = u->hw_dB_max = 0;
+    u->hw_volume_min = u->hw_volume_max = 0;
+
+    if (use_tsched)
+        fix_tsched_watermark(u);
+
+    u->sink->thread_info.max_rewind = use_tsched ? u->hwbuf_size : 0;
+    u->sink->max_latency = pa_bytes_to_usec(u->hwbuf_size, &ss);
+    if (!use_tsched)
+        u->sink->min_latency = u->sink->max_latency;
+
+    pa_log_info("Using %u fragments of size %lu bytes, buffer time is %0.2fms",
+                nfrags, (long unsigned) u->fragment_size,
+                (double) pa_bytes_to_usec(u->hwbuf_size, &ss) / PA_USEC_PER_MSEC);
+
+    if (use_tsched)
+        pa_log_info("Time scheduling watermark is %0.2fms",
+                    (double) pa_bytes_to_usec(u->tsched_watermark, &ss) / PA_USEC_PER_MSEC);
+
+    if (update_sw_params(u) < 0)
+        goto fail;
 
     pa_memchunk_reset(&u->memchunk);
 
@@ -895,17 +1339,74 @@ int pa__init(pa_module*m) {
         pa_assert(u->mixer_elem);
 
         if (snd_mixer_selem_has_playback_volume(u->mixer_elem))
-            if (pa_alsa_calc_mixer_map(u->mixer_elem, &map, u->mixer_map, TRUE) >= 0) {
-                u->sink->get_volume = sink_get_volume_cb;
-                u->sink->set_volume = sink_set_volume_cb;
-                snd_mixer_selem_get_playback_volume_range(u->mixer_elem, &u->hw_volume_min, &u->hw_volume_max);
-                u->sink->flags |= PA_SINK_HW_VOLUME_CTRL;
+
+            if (pa_alsa_calc_mixer_map(u->mixer_elem, &map, u->mixer_map, TRUE) >= 0 &&
+                snd_mixer_selem_get_playback_volume_range(u->mixer_elem, &u->hw_volume_min, &u->hw_volume_max) >= 0) {
+
+                pa_bool_t suitable = TRUE;
+
+                pa_log_info("Volume ranges from %li to %li.", u->hw_volume_min, u->hw_volume_max);
+
+                if (u->hw_volume_min > u->hw_volume_max) {
+
+                    pa_log_info("Minimal volume %li larger than maximum volume %li. Strange stuff Falling back to software volume control.", u->hw_volume_min, u->hw_volume_max);
+                    suitable = FALSE;
+
+                } else if (u->hw_volume_max - u->hw_volume_min < 3) {
+
+                    pa_log_info("Device has less than 4 volume levels. Falling back to software volume control.");
+                    suitable = FALSE;
+
+                } else if (snd_mixer_selem_get_playback_dB_range(u->mixer_elem, &u->hw_dB_min, &u->hw_dB_max) >= 0) {
+
+                    /* u->hw_dB_max = 0; u->hw_dB_min = -3000; Use this to make valgrind shut up */
+
+                    pa_log_info("Volume ranges from %0.2f dB to %0.2f dB.", u->hw_dB_min/100.0, u->hw_dB_max/100.0);
+
+                    /* Let's see if this thing actually is useful for muting */
+                    if (u->hw_dB_min > -6000) {
+                        pa_log_info("Device cannot attenuate for more than -60 dB (only %0.2f dB supported), falling back to software volume control.", ((double) u->hw_dB_min) / 100);
+
+                        suitable = FALSE;
+                    } else if (u->hw_dB_max < 0) {
+
+                        pa_log_info("Device is still attenuated at maximum volume setting (%0.2f dB is maximum). Strange stuff. Falling back to software volume control.", ((double) u->hw_dB_max) / 100);
+                        suitable = FALSE;
+
+                    } else if (u->hw_dB_min >= u->hw_dB_max) {
+
+                        pa_log_info("Minimal dB (%0.2f) larger or equal to maximum dB (%0.2f). Strange stuff. Falling back to software volume control.", ((double) u->hw_dB_min) / 100, ((double) u->hw_dB_max) / 100);
+                        suitable = FALSE;
+
+                    } else {
+
+                        if (u->hw_dB_max > 0) {
+                            /* dB > 0 means overamplification, and clipping, we don't want that here */
+                            pa_log_info("Device can do overamplification for %0.2f dB. Limiting to 0 db", ((double) u->hw_dB_max) / 100);
+                            u->hw_dB_max = 0;
+                        }
+
+                        u->hw_dB_supported = TRUE;
+                    }
+                }
+
+                if (suitable) {
+                    u->sink->get_volume = sink_get_volume_cb;
+                    u->sink->set_volume = sink_set_volume_cb;
+                    u->sink->flags |= PA_SINK_HW_VOLUME_CTRL | (u->hw_dB_supported ? PA_SINK_DECIBEL_VOLUME : 0);
+                    pa_log_info("Using hardware volume control. Hardware dB scale %s.", u->hw_dB_supported ? "supported" : "not supported");
+
+                } else if (mixer_reset) {
+                    pa_log_info("Using software volume control. Trying to reset sound card to 0 dB.");
+                    pa_alsa_0dB_playback(u->mixer_elem);
+                } else
+                    pa_log_info("Using software volume control. Leaving hw mixer controls untouched.");
             }
 
         if (snd_mixer_selem_has_playback_switch(u->mixer_elem)) {
             u->sink->get_mute = sink_get_mute_cb;
             u->sink->set_mute = sink_set_mute_cb;
-            u->sink->flags |= PA_SINK_HW_VOLUME_CTRL;
+            u->sink->flags |= PA_SINK_HW_MUTE_CTRL;
         }
 
         u->mixer_fdl = pa_alsa_fdlist_new();
@@ -920,16 +1421,29 @@ int pa__init(pa_module*m) {
     } else
         u->mixer_fdl = NULL;
 
+    pa_alsa_dump(u->pcm_handle);
+
     if (!(u->thread = pa_thread_new(thread_func, u))) {
         pa_log("Failed to create thread.");
         goto fail;
     }
 
     /* Get initial mixer settings */
-    if (u->sink->get_volume)
-        u->sink->get_volume(u->sink);
-    if (u->sink->get_mute)
-        u->sink->get_mute(u->sink);
+    if (data.volume_is_set) {
+        if (u->sink->set_volume)
+            u->sink->set_volume(u->sink);
+    } else {
+        if (u->sink->get_volume)
+            u->sink->get_volume(u->sink);
+    }
+
+    if (data.muted_is_set) {
+        if (u->sink->set_mute)
+            u->sink->set_mute(u->sink);
+    } else {
+        if (u->sink->get_mute)
+            u->sink->get_mute(u->sink);
+    }
 
     pa_sink_put(u->sink);
 
@@ -952,8 +1466,10 @@ void pa__done(pa_module*m) {
 
     pa_assert(m);
 
-    if (!(u = m->userdata))
+    if (!(u = m->userdata)) {
+        pa_alsa_redirect_errors_dec();
         return;
+    }
 
     if (u->sink)
         pa_sink_unlink(u->sink);
@@ -988,8 +1504,13 @@ void pa__done(pa_module*m) {
         snd_pcm_close(u->pcm_handle);
     }
 
+    if (u->smoother)
+        pa_smoother_free(u->smoother);
+
     pa_xfree(u->device_name);
     pa_xfree(u);
 
     snd_config_update_free_global();
+
+    pa_alsa_redirect_errors_dec();
 }