]> code.delx.au - pulseaudio/blobdiff - src/modules/module-alsa-source.c
Merge branch 'master' of ssh://rootserver/home/lennart/git/public/pulseaudio
[pulseaudio] / src / modules / module-alsa-source.c
index 3c6b8dbaf08e631cda9377cc72fea5d761040854..a6e4c9074cd3f03e3de2520b482423966f7c17da 100644 (file)
@@ -1,9 +1,7 @@
-/* $Id$ */
-
 /***
   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
 
 #include <asoundlib.h>
 
+#ifdef HAVE_VALGRIND_MEMCHECK_H
+#include <valgrind/memcheck.h>
+#endif
+
 #include <pulse/xmalloc.h>
 #include <pulse/util.h>
 #include <pulse/timeval.h>
@@ -71,8 +73,7 @@ PA_MODULE_USAGE(
         "mmap=<enable memory mapping?> "
         "tsched=<enable system timer based scheduling mode?> "
         "tsched_buffer_size=<buffer size when using timer based scheduling> "
-        "tsched_buffer_watermark=<upper fill watermark> "
-        "mixer_reset=<reset hw volume and mute settings to sane defaults when falling back to software?>");
+        "tsched_buffer_watermark=<upper fill watermark>");
 
 static const char* const valid_modargs[] = {
     "source_name",
@@ -88,15 +89,14 @@ static const char* const valid_modargs[] = {
     "tsched",
     "tsched_buffer_size",
     "tsched_buffer_watermark",
-    "mixer_reset",
     NULL
 };
 
 #define DEFAULT_DEVICE "default"
-#define DEFAULT_TSCHED_BUFFER_USEC (5*PA_USEC_PER_SEC)
-#define DEFAULT_TSCHED_WATERMARK_USEC (20*PA_USEC_PER_MSEC)
-#define TSCHED_MIN_SLEEP_USEC (3*PA_USEC_PER_MSEC)        /* 3ms */
-#define TSCHED_MIN_WAKEUP_USEC (3*PA_USEC_PER_MSEC)        /* 3ms */
+#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;
@@ -115,6 +115,9 @@ struct userdata {
     long hw_volume_max, hw_volume_min;
     long hw_dB_max, hw_dB_min;
     pa_bool_t hw_dB_supported;
+    pa_bool_t mixer_seperate_channels;
+
+    pa_cvolume hardware_volume;
 
     size_t frame_size, fragment_size, hwbuf_size, tsched_watermark;
     unsigned nfragments;
@@ -138,7 +141,7 @@ static void fix_tsched_watermark(struct userdata *u) {
     size_t min_sleep, min_wakeup;
     pa_assert(u);
 
-    max_use = u->hwbuf_size - u->hwbuf_unused_frames * u->frame_size;
+    max_use = u->hwbuf_size - (size_t) u->hwbuf_unused_frames * u->frame_size;
 
     min_sleep = pa_usec_to_bytes(TSCHED_MIN_SLEEP_USEC, &u->source->sample_spec);
     min_wakeup = pa_usec_to_bytes(TSCHED_MIN_WAKEUP_USEC, &u->source->sample_spec);
@@ -160,6 +163,31 @@ static void fix_tsched_watermark(struct userdata *u) {
         u->tsched_watermark = min_wakeup;
 }
 
+static pa_usec_t hw_sleep_time(struct userdata *u, pa_usec_t *sleep_usec, pa_usec_t*process_usec) {
+    pa_usec_t wm, usec;
+
+    pa_assert(u);
+
+    usec = pa_source_get_requested_latency_within_thread(u->source);
+
+    if (usec == (pa_usec_t) -1)
+        usec = pa_bytes_to_usec(u->hwbuf_size, &u->source->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->source->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)); */
+
+    return usec;
+}
+
 static int try_recover(struct userdata *u, const char *call, int err) {
     pa_assert(u);
     pa_assert(call);
@@ -167,10 +195,7 @@ static int try_recover(struct userdata *u, const char *call, int err) {
 
     pa_log_debug("%s: %s", call, snd_strerror(err));
 
-    if (err == -EAGAIN) {
-        pa_log_debug("%s: EAGAIN", call);
-        return 1;
-    }
+    pa_assert(err != -EAGAIN);
 
     if (err == -EPIPE)
         pa_log_debug("%s: Buffer overrun!", call);
@@ -184,17 +209,18 @@ static int try_recover(struct userdata *u, const char *call, int err) {
     return -1;
 }
 
-static void check_left_to_record(struct userdata *u, snd_pcm_sframes_t n) {
+static size_t check_left_to_record(struct userdata *u, snd_pcm_sframes_t n) {
     size_t left_to_record;
+    size_t rec_space = u->hwbuf_size - (size_t) u->hwbuf_unused_frames*u->frame_size;
 
-    if (n*u->frame_size < u->hwbuf_size)
-        left_to_record = u->hwbuf_size - (n*u->frame_size);
+    if ((size_t) n*u->frame_size < rec_space)
+        left_to_record = rec_space - ((size_t) n*u->frame_size);
     else
         left_to_record = 0;
 
-    if (left_to_record > 0)
-        pa_log_debug("%0.2f ms left to record", (double) pa_bytes_to_usec(left_to_record, &u->source->sample_spec) / PA_USEC_PER_MSEC);
-    else {
+    if (left_to_record > 0) {
+/*         pa_log_debug("%0.2f ms left to record", (double) pa_bytes_to_usec(left_to_record, &u->source->sample_spec) / PA_USEC_PER_MSEC); */
+    else {
         pa_log_info("Overrun!");
 
         if (u->use_tsched) {
@@ -208,173 +234,210 @@ static void check_left_to_record(struct userdata *u, snd_pcm_sframes_t n) {
                               (double) pa_bytes_to_usec(u->tsched_watermark, &u->source->sample_spec) / PA_USEC_PER_MSEC);
         }
     }
+
+    return left_to_record;
 }
 
-static int mmap_read(struct userdata *u) {
+static int mmap_read(struct userdata *u, pa_usec_t *sleep_usec, pa_bool_t polled) {
     int work_done = 0;
-    pa_bool_t checked_left_to_record = FALSE;
+    pa_usec_t max_sleep_usec = 0, process_usec = 0;
+    size_t left_to_record;
 
     pa_assert(u);
     pa_source_assert_ref(u->source);
 
+    if (u->use_tsched)
+        hw_sleep_time(u, &max_sleep_usec, &process_usec);
+
     for (;;) {
         snd_pcm_sframes_t n;
-        int err, r;
-        const snd_pcm_channel_area_t *areas;
-        snd_pcm_uframes_t offset, frames;
-        pa_memchunk chunk;
-        void *p;
+        int r;
 
         snd_pcm_hwsync(u->pcm_handle);
 
-        if (PA_UNLIKELY((n = snd_pcm_avail_update(u->pcm_handle)) < 0)) {
+        if (PA_UNLIKELY((n = pa_alsa_safe_avail_update(u->pcm_handle, u->hwbuf_size, &u->source->sample_spec)) < 0)) {
 
-            if ((r = try_recover(u, "snd_pcm_avail_update", err)) == 0)
+            if ((r = try_recover(u, "snd_pcm_avail_update", (int) n)) == 0)
                 continue;
-            else if (r > 0)
-                return work_done;
 
             return r;
         }
 
-        if (checked_left_to_record) {
-            check_left_to_record(u, n);
-            checked_left_to_record = TRUE;
+        left_to_record = check_left_to_record(u, n);
+
+        if (u->use_tsched)
+            if (!polled &&
+                pa_bytes_to_usec(left_to_record, &u->source->sample_spec) > process_usec+max_sleep_usec/2)
+                break;
+
+        if (PA_UNLIKELY(n <= 0)) {
+
+            if (polled)
+                pa_log("ALSA woke us up to read new data from the device, but there was actually nothing to read! "
+                       "Most likely this is an ALSA driver bug. Please report this issue to the PulseAudio device.");
+
+            break;
         }
 
-        if (PA_UNLIKELY(n <= 0))
-            return work_done;
+        polled = FALSE;
 
-        frames = n;
+        for (;;) {
+            int err;
+            const snd_pcm_channel_area_t *areas;
+            snd_pcm_uframes_t offset, frames = (snd_pcm_uframes_t) n;
+            pa_memchunk chunk;
+            void *p;
+            snd_pcm_sframes_t sframes;
 
-        pa_log_debug("%lu frames to read", (unsigned long) frames);
+/*             pa_log_debug("%lu frames to read", (unsigned long) frames); */
 
-        if (PA_UNLIKELY((err = snd_pcm_mmap_begin(u->pcm_handle, &areas, &offset, &frames)) < 0)) {
+            if (PA_UNLIKELY((err = pa_alsa_safe_mmap_begin(u->pcm_handle, &areas, &offset, &frames, u->hwbuf_size, &u->source->sample_spec)) < 0)) {
 
-            if ((r = try_recover(u, "snd_pcm_mmap_begin", err)) == 0)
-                continue;
-            else if (r > 0)
-                return work_done;
+                if ((r = try_recover(u, "snd_pcm_mmap_begin", err)) == 0)
+                    continue;
 
-            return r;
-        }
+                return r;
+            }
 
-        /* Make sure that if these memblocks need to be copied they will fit into one slot */
-        if (frames > pa_mempool_block_size_max(u->source->core->mempool)/u->frame_size)
-            frames = pa_mempool_block_size_max(u->source->core->mempool)/u->frame_size;
+            /* Make sure that if these memblocks need to be copied they will fit into one slot */
+            if (frames > pa_mempool_block_size_max(u->source->core->mempool)/u->frame_size)
+                frames = pa_mempool_block_size_max(u->source->core->mempool)/u->frame_size;
 
-        /* Check these are multiples of 8 bit */
-        pa_assert((areas[0].first & 7) == 0);
-        pa_assert((areas[0].step & 7)== 0);
+            /* Check these are multiples of 8 bit */
+            pa_assert((areas[0].first & 7) == 0);
+            pa_assert((areas[0].step & 7)== 0);
 
-        /* We assume a single interleaved memory buffer */
-        pa_assert((areas[0].first >> 3) == 0);
-        pa_assert((areas[0].step >> 3) == u->frame_size);
+            /* We assume a single interleaved memory buffer */
+            pa_assert((areas[0].first >> 3) == 0);
+            pa_assert((areas[0].step >> 3) == u->frame_size);
 
-        p = (uint8_t*) areas[0].addr + (offset * u->frame_size);
+            p = (uint8_t*) areas[0].addr + (offset * u->frame_size);
 
-        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;
+            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;
 
-        pa_source_post(u->source, &chunk);
-        pa_memblock_unref_fixed(chunk.memblock);
+            pa_source_post(u->source, &chunk);
+            pa_memblock_unref_fixed(chunk.memblock);
 
-        if (PA_UNLIKELY((err = snd_pcm_mmap_commit(u->pcm_handle, offset, frames)) < 0)) {
+            if (PA_UNLIKELY((sframes = snd_pcm_mmap_commit(u->pcm_handle, offset, frames)) < 0)) {
 
-            if ((r = try_recover(u, "snd_pcm_mmap_commit", err)) == 0)
-                continue;
-            else if (r > 0)
-                return work_done;
+                if ((r = try_recover(u, "snd_pcm_mmap_commit", (int) sframes)) == 0)
+                    continue;
 
-            return r;
-        }
+                return r;
+            }
 
-        work_done = 1;
+            work_done = 1;
 
-        u->frame_index += frames;
+            u->frame_index += (int64_t) frames;
 
-        pa_log_debug("read %lu frames", (unsigned long) frames);
+/*             pa_log_debug("read %lu frames", (unsigned long) frames); */
 
-        if (PA_LIKELY(frames >= (snd_pcm_uframes_t) n))
-            return work_done;
+            if (frames >= (snd_pcm_uframes_t) n)
+                break;
+
+            n -= (snd_pcm_sframes_t) frames;
+        }
     }
+
+    *sleep_usec = pa_bytes_to_usec(left_to_record, &u->source->sample_spec) - process_usec;
+    return work_done;
 }
 
-static int unix_read(struct userdata *u) {
+static int unix_read(struct userdata *u, pa_usec_t *sleep_usec, pa_bool_t polled) {
     int work_done = 0;
-    pa_bool_t checked_left_to_record = FALSE;
+    pa_usec_t max_sleep_usec = 0, process_usec = 0;
+    size_t left_to_record;
 
     pa_assert(u);
     pa_source_assert_ref(u->source);
 
+    if (u->use_tsched)
+        hw_sleep_time(u, &max_sleep_usec, &process_usec);
+
     for (;;) {
-        void *p;
-        snd_pcm_sframes_t n, frames;
+        snd_pcm_sframes_t n;
         int r;
-        pa_memchunk chunk;
 
         snd_pcm_hwsync(u->pcm_handle);
 
-        if (PA_UNLIKELY((n = snd_pcm_avail_update(u->pcm_handle)) < 0)) {
+        if (PA_UNLIKELY((n = pa_alsa_safe_avail_update(u->pcm_handle, u->hwbuf_size, &u->source->sample_spec)) < 0)) {
 
-            if ((r = try_recover(u, "snd_pcm_avail_update", n)) == 0)
+            if ((r = try_recover(u, "snd_pcm_avail_update", (int) n)) == 0)
                 continue;
-            else if (r > 0)
-                return work_done;
 
             return r;
         }
 
-        if (checked_left_to_record) {
-            check_left_to_record(u, n);
-            checked_left_to_record = TRUE;
-        }
+        left_to_record = check_left_to_record(u, n);
+
+        if (u->use_tsched)
+            if (!polled &&
+                pa_bytes_to_usec(left_to_record, &u->source->sample_spec) > process_usec+max_sleep_usec/2)
+                break;
+
+        if (PA_UNLIKELY(n <= 0)) {
+
+            if (polled)
+                pa_log("ALSA woke us up to read new data from the device, but there was actually nothing to read! "
+                       "Most likely this is an ALSA driver bug. Please report this issue to the PulseAudio developers.");
 
-        if (PA_UNLIKELY(n <= 0))
             return work_done;
+        }
 
-        chunk.memblock = pa_memblock_new(u->core->mempool, (size_t) -1);
+        polled = FALSE;
 
-        frames = pa_memblock_get_length(chunk.memblock) / u->frame_size;
+        for (;;) {
+            void *p;
+            snd_pcm_sframes_t frames;
+            pa_memchunk chunk;
 
-        if (frames > n)
-            frames = n;
+            chunk.memblock = pa_memblock_new(u->core->mempool, (size_t) -1);
 
-        pa_log_debug("%lu frames to read", (unsigned long) n);
+            frames = (snd_pcm_sframes_t) (pa_memblock_get_length(chunk.memblock) / u->frame_size);
 
-        p = pa_memblock_acquire(chunk.memblock);
-        frames = snd_pcm_readi(u->pcm_handle, (uint8_t*) p, frames);
-        pa_memblock_release(chunk.memblock);
+            if (frames > n)
+                frames = n;
 
-        pa_assert(frames != 0);
+/*             pa_log_debug("%lu frames to read", (unsigned long) n); */
 
-        if (PA_UNLIKELY(frames < 0)) {
-            pa_memblock_unref(chunk.memblock);
+            p = pa_memblock_acquire(chunk.memblock);
+            frames = snd_pcm_readi(u->pcm_handle, (uint8_t*) p, (snd_pcm_uframes_t) frames);
+            pa_memblock_release(chunk.memblock);
 
-            if ((r = try_recover(u, "snd_pcm_readi", n)) == 0)
-                continue;
-            else if (r > 0)
-                return work_done;
+            pa_assert(frames != 0);
 
-            return r;
-        }
+            if (PA_UNLIKELY(frames < 0)) {
+                pa_memblock_unref(chunk.memblock);
+
+                if ((r = try_recover(u, "snd_pcm_readi", (int) (frames))) == 0)
+                    continue;
+
+                return r;
+            }
+
+            chunk.index = 0;
+            chunk.length = (size_t) frames * u->frame_size;
 
-        chunk.index = 0;
-        chunk.length = frames * u->frame_size;
+            pa_source_post(u->source, &chunk);
+            pa_memblock_unref(chunk.memblock);
 
-        pa_source_post(u->source, &chunk);
-        pa_memblock_unref(chunk.memblock);
+            work_done = 1;
 
-        work_done = 1;
+            u->frame_index += frames;
 
-        u->frame_index += frames;
+/*             pa_log_debug("read %lu frames", (unsigned long) frames); */
 
-        pa_log_debug("read %lu frames", (unsigned long) frames);
+            if (frames >= n)
+                break;
 
-        if (PA_LIKELY(frames >= n))
-            return work_done;
+            n -= frames;
+        }
     }
+
+    *sleep_usec = pa_bytes_to_usec(left_to_record, &u->source->sample_spec) - process_usec;
+    return work_done;
 }
 
 static void update_smoother(struct userdata *u) {
@@ -399,7 +462,7 @@ static void update_smoother(struct userdata *u) {
     frames = u->frame_index + delay;
 
     now1 = pa_rtclock_usec();
-    now2 = pa_bytes_to_usec(frames * u->frame_size, &u->source->sample_spec);
+    now2 = pa_bytes_to_usec((uint64_t) frames * u->frame_size, &u->source->sample_spec);
 
     pa_smoother_put(u->smoother, now1, now2);
 }
@@ -414,7 +477,7 @@ static pa_usec_t source_get_latency(struct userdata *u) {
     now1 = pa_rtclock_usec();
     now2 = pa_smoother_get(u->smoother, now1);
 
-    delay = (int64_t) now2 - pa_bytes_to_usec(u->frame_index * u->frame_size, &u->source->sample_spec);
+    delay = (int64_t) now2 - (int64_t) pa_bytes_to_usec((uint64_t) u->frame_index * u->frame_size, &u->source->sample_spec);
 
     if (delay > 0)
         r = (pa_usec_t) delay;
@@ -455,30 +518,6 @@ static int suspend(struct userdata *u) {
     return 0;
 }
 
-static pa_usec_t hw_sleep_time(struct userdata *u) {
-    pa_usec_t wm, usec;
-
-    pa_assert(u);
-
-    usec = pa_source_get_requested_latency_within_thread(u->source);
-
-    if (usec == (pa_usec_t) -1)
-        usec = pa_bytes_to_usec(u->hwbuf_size, &u->source->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->source->sample_spec);
-
-    if (usec >= wm)
-        usec -= wm;
-    else
-        usec /= 2;
-
-/*     pa_log_debug("after watermark: %u ms", (unsigned) (usec / PA_USEC_PER_MSEC)); */
-
-    return usec;
-}
-
 static int update_sw_params(struct userdata *u) {
     snd_pcm_uframes_t avail_min;
     int err;
@@ -494,7 +533,7 @@ static int update_sw_params(struct userdata *u) {
         if ((latency = pa_source_get_requested_latency_within_thread(u->source)) != (pa_usec_t) -1) {
             size_t b;
 
-            pa_log_debug("latency set to %0.2f", (double) latency / PA_USEC_PER_MSEC);
+            pa_log_debug("latency set to %0.2fms", (double) latency / PA_USEC_PER_MSEC);
 
             b = pa_usec_to_bytes(latency, &u->source->sample_spec);
 
@@ -503,12 +542,12 @@ static int update_sw_params(struct userdata *u) {
             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);
+            u->hwbuf_unused_frames = (snd_pcm_sframes_t)
+                (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);
@@ -516,10 +555,10 @@ static int update_sw_params(struct userdata *u) {
     avail_min = 1;
 
     if (u->use_tsched) {
-        pa_usec_t usec;
+        pa_usec_t sleep_usec, process_usec;
 
-        usec = hw_sleep_time(u);
-        avail_min += pa_usec_to_bytes(usec, &u->source->sample_spec);
+        hw_sleep_time(u, &sleep_usec, &process_usec);
+        avail_min += pa_usec_to_bytes(sleep_usec, &u->source->sample_spec);
     }
 
     pa_log_debug("setting avail_min=%lu", (unsigned long) avail_min);
@@ -545,7 +584,12 @@ static int unsuspend(struct userdata *u) {
     pa_log_info("Trying resume...");
 
     snd_config_update_free_global();
-    if ((err = snd_pcm_open(&u->pcm_handle, u->device_name, SND_PCM_STREAM_CAPTURE, SND_PCM_NONBLOCK)) < 0) {
+
+    if ((err = snd_pcm_open(&u->pcm_handle, u->device_name, SND_PCM_STREAM_CAPTURE,
+                            /*SND_PCM_NONBLOCK|*/
+                            SND_PCM_NO_AUTO_RESAMPLE|
+                            SND_PCM_NO_AUTO_CHANNELS|
+                            SND_PCM_NO_AUTO_FORMAT)) < 0) {
         pa_log("Error opening PCM device %s: %s", u->device_name, snd_strerror(err));
         goto fail;
     }
@@ -572,7 +616,9 @@ static int unsuspend(struct userdata *u) {
     }
 
     if (nfrags != u->nfragments || period_size*u->frame_size != u->fragment_size) {
-        pa_log_warn("Resume failed, couldn't restore original fragment settings.");
+        pa_log_warn("Resume failed, couldn't restore original fragment settings. (Old: %lu*%lu, New %lu*%lu)",
+                    (unsigned long) u->nfragments, (unsigned long) u->fragment_size,
+                    (unsigned long) nfrags, period_size * u->frame_size);
         goto fail;
     }
 
@@ -621,7 +667,7 @@ static int source_process_msg(pa_msgobject *o, int code, void *data, int64_t off
             switch ((pa_source_state_t) PA_PTR_TO_UINT(data)) {
 
                 case PA_SOURCE_SUSPENDED:
-                    pa_assert(PA_SOURCE_OPENED(u->source->thread_info.state));
+                    pa_assert(PA_SOURCE_IS_OPENED(u->source->thread_info.state));
 
                     if (suspend(u) < 0)
                         return -1;
@@ -666,40 +712,101 @@ static int mixer_callback(snd_mixer_elem_t *elem, unsigned int mask) {
         return 0;
 
     if (mask & SND_CTL_EVENT_MASK_VALUE) {
-        pa_source_get_volume(u->source);
-        pa_source_get_mute(u->source);
+        pa_source_get_volume(u->source, TRUE);
+        pa_source_get_mute(u->source, TRUE);
     }
 
     return 0;
 }
 
+static pa_volume_t from_alsa_volume(struct userdata *u, long alsa_vol) {
+
+    return (pa_volume_t) round(((double) (alsa_vol - u->hw_volume_min) * PA_VOLUME_NORM) /
+                               (double) (u->hw_volume_max - u->hw_volume_min));
+}
+
+static long to_alsa_volume(struct userdata *u, pa_volume_t vol) {
+    long alsa_vol;
+
+    alsa_vol = (long) round(((double) vol * (double) (u->hw_volume_max - u->hw_volume_min))
+                            / PA_VOLUME_NORM) + u->hw_volume_min;
+
+    return PA_CLAMP_UNLIKELY(alsa_vol, u->hw_volume_min, u->hw_volume_max);
+}
+
 static int source_get_volume_cb(pa_source *s) {
     struct userdata *u = s->userdata;
     int err;
-    int i;
+    unsigned i;
+    pa_cvolume r;
+    char t[PA_CVOLUME_SNPRINT_MAX];
 
     pa_assert(u);
     pa_assert(u->mixer_elem);
 
-    for (i = 0; i < s->sample_spec.channels; i++) {
-        long alsa_vol;
+    if (u->mixer_seperate_channels) {
 
-        pa_assert(snd_mixer_selem_has_capture_channel(u->mixer_elem, u->mixer_map[i]));
+        r.channels = s->sample_spec.channels;
 
-        if (u->hw_dB_supported) {
+        for (i = 0; i < s->sample_spec.channels; i++) {
+            long alsa_vol;
 
-            if ((err = snd_mixer_selem_get_capture_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;
+            if (u->hw_dB_supported) {
+
+                if ((err = snd_mixer_selem_get_capture_dB(u->mixer_elem, u->mixer_map[i], &alsa_vol)) < 0)
+                    goto fail;
+
+#ifdef HAVE_VALGRIND_MEMCHECK_H
+                VALGRIND_MAKE_MEM_DEFINED(&alsa_vol, sizeof(alsa_vol));
+#endif
+
+                r.values[i] = pa_sw_volume_from_dB((double) (alsa_vol - u->hw_dB_max) / 100.0);
+            } else {
+
+                if ((err = snd_mixer_selem_get_capture_volume(u->mixer_elem, u->mixer_map[i], &alsa_vol)) < 0)
+                    goto fail;
+
+                r.values[i] = from_alsa_volume(u, alsa_vol);
             }
+        }
+
+    } else {
+        long alsa_vol;
 
-            u->hw_dB_supported = FALSE;
+        if (u->hw_dB_supported) {
+
+            if ((err = snd_mixer_selem_get_capture_dB(u->mixer_elem, SND_MIXER_SCHN_MONO, &alsa_vol)) < 0)
+                goto fail;
+
+#ifdef HAVE_VALGRIND_MEMCHECK_H
+            VALGRIND_MAKE_MEM_DEFINED(&alsa_vol, sizeof(alsa_vol));
+#endif
+
+            pa_cvolume_set(&r, s->sample_spec.channels, pa_sw_volume_from_dB((double) (alsa_vol - u->hw_dB_max) / 100.0));
+
+        } else {
+
+            if ((err = snd_mixer_selem_get_capture_volume(u->mixer_elem, SND_MIXER_SCHN_MONO, &alsa_vol)) < 0)
+                goto fail;
+
+            pa_cvolume_set(&r, s->sample_spec.channels, from_alsa_volume(u, alsa_vol));
         }
+    }
 
-        if ((err = snd_mixer_selem_get_capture_volume(u->mixer_elem, u->mixer_map[i], &alsa_vol)) < 0)
-            goto fail;
+    pa_log_debug("Read hardware volume: %s", pa_cvolume_snprint(t, sizeof(t), &r));
+
+    if (!pa_cvolume_equal(&u->hardware_volume, &r)) {
 
-        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));
+        u->hardware_volume = s->volume = r;
+
+        if (u->hw_dB_supported) {
+            pa_cvolume reset;
+
+            /* Hmm, so the hardware volume changed, let's reset our software volume */
+
+            pa_cvolume_reset(&reset, s->sample_spec.channels);
+            pa_source_set_soft_volume(s, &reset);
+        }
     }
 
     return 0;
@@ -713,44 +820,101 @@ fail:
 static int source_set_volume_cb(pa_source *s) {
     struct userdata *u = s->userdata;
     int err;
-    int i;
+    unsigned i;
+    pa_cvolume r;
 
     pa_assert(u);
     pa_assert(u->mixer_elem);
 
-    for (i = 0; i < s->sample_spec.channels; i++) {
-        long alsa_vol;
-        pa_volume_t vol;
+    if (u->mixer_seperate_channels) {
+
+        r.channels = s->sample_spec.channels;
+
+        for (i = 0; i < s->sample_spec.channels; i++) {
+            long alsa_vol;
+            pa_volume_t vol;
+
+            vol = s->volume.values[i];
+
+            if (u->hw_dB_supported) {
+
+                alsa_vol = (long) (pa_sw_volume_to_dB(vol) * 100);
+                alsa_vol += u->hw_dB_max;
+                alsa_vol = PA_CLAMP_UNLIKELY(alsa_vol, u->hw_dB_min, u->hw_dB_max);
+
+                if ((err = snd_mixer_selem_set_capture_dB(u->mixer_elem, u->mixer_map[i], alsa_vol, 1)) < 0)
+                    goto fail;
+
+                if ((err = snd_mixer_selem_get_capture_dB(u->mixer_elem, u->mixer_map[i], &alsa_vol)) < 0)
+                    goto fail;
+
+                r.values[i] = pa_sw_volume_from_dB((double) (alsa_vol - u->hw_dB_max) / 100.0);
 
-        pa_assert(snd_mixer_selem_has_capture_channel(u->mixer_elem, u->mixer_map[i]));
+            } else {
+                alsa_vol = to_alsa_volume(u, vol);
 
-        vol = PA_MIN(s->volume.values[i], PA_VOLUME_NORM);
+                if ((err = snd_mixer_selem_set_capture_volume(u->mixer_elem, u->mixer_map[i], alsa_vol)) < 0)
+                    goto fail;
+
+                if ((err = snd_mixer_selem_get_capture_volume(u->mixer_elem, u->mixer_map[i], &alsa_vol)) < 0)
+                    goto fail;
+
+                r.values[i] = from_alsa_volume(u, alsa_vol);
+            }
+        }
+
+    } else {
+        pa_volume_t vol;
+        long alsa_vol;
+
+        vol = pa_cvolume_max(&s->volume);
 
         if (u->hw_dB_supported) {
             alsa_vol = (long) (pa_sw_volume_to_dB(vol) * 100);
+            alsa_vol += u->hw_dB_max;
             alsa_vol = PA_CLAMP_UNLIKELY(alsa_vol, u->hw_dB_min, u->hw_dB_max);
 
+            if ((err = snd_mixer_selem_set_capture_dB_all(u->mixer_elem, alsa_vol, 1)) < 0)
+                goto fail;
 
-            if ((err = snd_mixer_selem_set_capture_dB(u->mixer_elem, u->mixer_map[i], alsa_vol, -1)) >= 0) {
+            if ((err = snd_mixer_selem_get_capture_dB(u->mixer_elem, SND_MIXER_SCHN_MONO, &alsa_vol)) < 0)
+                goto fail;
 
-                if (snd_mixer_selem_get_capture_dB(u->mixer_elem, u->mixer_map[i], &alsa_vol) >= 0)
-                    s->volume.values[i] = pa_sw_volume_from_dB(alsa_vol / 100.0);
+            pa_cvolume_set(&r, s->volume.channels, pa_sw_volume_from_dB((double) (alsa_vol - u->hw_dB_max) / 100.0));
 
-                continue;
-            }
+        } else {
+            alsa_vol = to_alsa_volume(u, vol);
 
-            u->hw_dB_supported = FALSE;
+            if ((err = snd_mixer_selem_set_capture_volume_all(u->mixer_elem, alsa_vol)) < 0)
+                goto fail;
+
+            if ((err = snd_mixer_selem_get_capture_volume(u->mixer_elem, SND_MIXER_SCHN_MONO, &alsa_vol)) < 0)
+                goto fail;
+
+            pa_cvolume_set(&r, s->sample_spec.channels, from_alsa_volume(u, alsa_vol));
         }
+    }
 
-        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);
+    u->hardware_volume = r;
 
-        if ((err = snd_mixer_selem_set_capture_volume(u->mixer_elem, u->mixer_map[i], alsa_vol)) < 0)
-            goto fail;
+    if (u->hw_dB_supported) {
+        char t[PA_CVOLUME_SNPRINT_MAX];
 
-        if (snd_mixer_selem_get_capture_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));
-    }
+        /* Match exactly what the user requested by software */
+
+        pa_sw_cvolume_divide(&r, &s->volume, &r);
+        pa_source_set_soft_volume(s, &r);
+
+        pa_log_debug("Requested volume: %s", pa_cvolume_snprint(t, sizeof(t), &s->volume));
+        pa_log_debug("Got hardware volume: %s", pa_cvolume_snprint(t, sizeof(t), &u->hardware_volume));
+        pa_log_debug("Calculated software volume: %s", pa_cvolume_snprint(t, sizeof(t), &r));
+
+    } else
+
+        /* We can't match exactly what the user requested, hence let's
+         * at least tell the user about it */
+
+        s->volume = r;
 
     return 0;
 
@@ -794,14 +958,17 @@ static int source_set_mute_cb(pa_source *s) {
 
 static void source_update_requested_latency_cb(pa_source *s) {
     struct userdata *u = s->userdata;
-
     pa_assert(u);
 
+    if (!u->pcm_handle)
+        return;
+
     update_sw_params(u);
 }
 
 static void thread_func(void *userdata) {
     struct userdata *u = userdata;
+    unsigned short revents = 0;
 
     pa_assert(u);
 
@@ -816,43 +983,42 @@ static void thread_func(void *userdata) {
     for (;;) {
         int ret;
 
-        pa_log_debug("loop");
+/*         pa_log_debug("loop"); */
 
         /* Read some data and pass it to the sources */
-        if (PA_SOURCE_OPENED(u->source->thread_info.state)) {
+        if (PA_SOURCE_IS_OPENED(u->source->thread_info.state)) {
             int work_done = 0;
+            pa_usec_t sleep_usec = 0;
 
             if (u->use_mmap)
-                work_done = mmap_read(u);
+                work_done = mmap_read(u, &sleep_usec, revents & POLLIN);
             else
-                work_done = unix_read(u);
+                work_done = unix_read(u, &sleep_usec, revents & POLLIN);
 
             if (work_done < 0)
                 goto fail;
 
-            pa_log_debug("work_done = %i", work_done);
+/*             pa_log_debug("work_done = %i", work_done); */
 
             if (work_done)
                 update_smoother(u);
 
             if (u->use_tsched) {
-                pa_usec_t usec, cusec;
+                pa_usec_t cusec;
 
                 /* OK, the capture buffer is now empty, let's
                  * calculate when to wake up next */
 
-                usec = hw_sleep_time(u);
-
-                pa_log_debug("Waking up in %0.2fms (sound card clock).", (double) usec / PA_USEC_PER_MSEC);
+/*                 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(), usec);
+                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);
+/*                 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(usec, cusec));
+                pa_rtpoll_set_timer_relative(u->rtpoll, PA_MIN(sleep_usec, cusec));
             }
         } else if (u->use_tsched)
 
@@ -860,16 +1026,15 @@ static void thread_func(void *userdata) {
             pa_rtpoll_set_timer_disabled(u->rtpoll);
 
         /* Hmm, nothing to do. Let's sleep */
-        if ((ret = pa_rtpoll_run(u->rtpoll, 1)) < 0)
+        if ((ret = pa_rtpoll_run(u->rtpoll, TRUE)) < 0)
             goto fail;
 
         if (ret == 0)
             goto finish;
 
         /* Tell ALSA about this and process its response */
-        if (PA_SOURCE_OPENED(u->source->thread_info.state)) {
+        if (PA_SOURCE_IS_OPENED(u->source->thread_info.state)) {
             struct pollfd *pollfd;
-            unsigned short revents = 0;
             int err;
             unsigned n;
 
@@ -880,16 +1045,17 @@ static void thread_func(void *userdata) {
                 goto fail;
             }
 
-            if (revents & (POLLERR|POLLNVAL|POLLHUP)) {
+            if (revents & (POLLOUT|POLLERR|POLLNVAL|POLLHUP|POLLPRI)) {
                 if (pa_alsa_recover_from_poll(u->pcm_handle, revents) < 0)
                     goto fail;
 
                 snd_pcm_start(u->pcm_handle);
             }
 
-            if (revents)
-                pa_log_debug("Wakeup from ALSA! (%i)", revents);
-        }
+            if (revents && u->use_tsched)
+                pa_log_debug("Wakeup from ALSA!%s%s", (revents & POLLIN) ? " INPUT" : "", (revents & POLLOUT) ? " OUTPUT" : "");
+        } else
+            revents = 0;
     }
 
 fail:
@@ -917,7 +1083,7 @@ int pa__init(pa_module*m) {
     const char *name;
     char *name_buf = NULL;
     pa_bool_t namereg_fail;
-    pa_bool_t use_mmap = TRUE, b, use_tsched = TRUE, d, mixer_reset = TRUE;
+    pa_bool_t use_mmap = TRUE, b, use_tsched = TRUE, d;
     pa_source_new_data data;
 
     snd_pcm_info_alloca(&pcm_info);
@@ -940,11 +1106,11 @@ 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*PA_USEC_PER_MSEC, &ss);
+    frag_size = (uint32_t) 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);
+        frag_size = (uint32_t) frame_size;
+    tsched_size = (uint32_t) pa_usec_to_bytes(DEFAULT_TSCHED_BUFFER_USEC, &ss);
+    tsched_watermark = (uint32_t) 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 ||
@@ -969,15 +1135,10 @@ int pa__init(pa_module*m) {
     }
 
     if (use_tsched && !pa_rtclock_hrtimer()) {
-        pa_log("Disabling timer-based scheduling because high-resolution timers are not available from the kernel.");
+        pa_log_notice("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;
@@ -988,7 +1149,7 @@ int pa__init(pa_module*m) {
     pa_thread_mq_init(&u->thread_mq, m->core->mainloop, u->rtpoll);
     u->alsa_rtpoll_item = NULL;
 
-    u->smoother = pa_smoother_new(DEFAULT_TSCHED_WATERMARK_USEC, DEFAULT_TSCHED_WATERMARK_USEC, TRUE);
+    u->smoother = pa_smoother_new(DEFAULT_TSCHED_WATERMARK_USEC, DEFAULT_TSCHED_WATERMARK_USEC, TRUE, 5);
     pa_smoother_set_time_offset(u->smoother, pa_rtclock_usec());
 
     snd_config_update_free_global();
@@ -1075,7 +1236,7 @@ int pa__init(pa_module*m) {
         }
 
         if (found)
-            if (!(u->mixer_elem = pa_alsa_find_elem(u->mixer_handle, "Capture", "Mic")))
+            if (!(u->mixer_elem = pa_alsa_find_elem(u->mixer_handle, "Capture", "Mic", FALSE)))
                 found = FALSE;
 
         if (!found) {
@@ -1122,7 +1283,7 @@ int pa__init(pa_module*m) {
     pa_source_set_rtpoll(u->source, u->rtpoll);
 
     u->frame_size = frame_size;
-    u->fragment_size = frag_size = period_frames * frame_size;
+    u->fragment_size = frag_size = (uint32_t) (period_frames * frame_size);
     u->nfragments = nfrags;
     u->hwbuf_size = u->fragment_size * nfrags;
     u->hwbuf_unused_frames = 0;
@@ -1131,13 +1292,15 @@ int pa__init(pa_module*m) {
     u->hw_dB_supported = FALSE;
     u->hw_dB_min = u->hw_dB_max = 0;
     u->hw_volume_min = u->hw_volume_max = 0;
+    u->mixer_seperate_channels = FALSE;
+    pa_cvolume_mute(&u->hardware_volume, u->source->sample_spec.channels);
 
     if (use_tsched)
         fix_tsched_watermark(u);
 
-    u->source->max_latency = pa_bytes_to_usec(u->hwbuf_size, &ss);
-    if (!use_tsched)
-        u->source->min_latency = u->source->max_latency;
+    pa_source_set_latency_range(u->source,
+                                !use_tsched ? pa_bytes_to_usec(u->hwbuf_size, &ss) : (pa_usec_t) -1,
+                                pa_bytes_to_usec(u->hwbuf_size, &ss));
 
     pa_log_info("Using %u fragments of size %lu bytes, buffer time is %0.2fms",
                 nfrags, (long unsigned) u->fragment_size,
@@ -1153,67 +1316,67 @@ int pa__init(pa_module*m) {
     if (u->mixer_handle) {
         pa_assert(u->mixer_elem);
 
-        if (snd_mixer_selem_has_capture_volume(u->mixer_elem))
-            if (pa_alsa_calc_mixer_map(u->mixer_elem, &map, u->mixer_map, FALSE) >= 0 &&
-                snd_mixer_selem_get_capture_volume_range(u->mixer_elem, &u->hw_volume_min, &u->hw_volume_max) >= 0) {
-
-                pa_bool_t suitable = TRUE;
+        if (snd_mixer_selem_has_capture_volume(u->mixer_elem)) {
+            pa_bool_t suitable = FALSE;
 
+            if (snd_mixer_selem_get_capture_volume_range(u->mixer_elem, &u->hw_volume_min, &u->hw_volume_max) < 0)
+                pa_log_info("Failed to get volume range. Falling back to software volume control.");
+            else if (u->hw_volume_min >= u->hw_volume_max)
+                pa_log_warn("Your kernel driver is broken: it reports a volume range from %li to %li which makes no sense.", u->hw_volume_min, u->hw_volume_max);
+            else {
                 pa_log_info("Volume ranges from %li to %li.", u->hw_volume_min, u->hw_volume_max);
+                suitable = TRUE;
+            }
 
-                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_capture_dB_range(u->mixer_elem, &u->hw_dB_min, &u->hw_dB_max) >= 0) {
-
-                    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;
+            if (suitable) {
+                if (snd_mixer_selem_get_capture_dB_range(u->mixer_elem, &u->hw_dB_min, &u->hw_dB_max) < 0)
+                    pa_log_info("Mixer doesn't support dB information.");
+                else {
+#ifdef HAVE_VALGRIND_MEMCHECK_H
+                    VALGRIND_MAKE_MEM_DEFINED(&u->hw_dB_min, sizeof(u->hw_dB_min));
+                    VALGRIND_MAKE_MEM_DEFINED(&u->hw_dB_max, sizeof(u->hw_dB_max));
+#endif
 
-                    } else if (u->hw_dB_min >= u->hw_dB_max) {
+                    if (u->hw_dB_min >= u->hw_dB_max)
+                        pa_log_warn("Your kernel driver is broken: it reports a volume range from %0.2f dB to %0.2f dB which makes no sense.", (double) u->hw_dB_min/100.0, (double) u->hw_dB_max/100.0);
+                    else {
+                        pa_log_info("Volume ranges from %0.2f dB to %0.2f dB.", (double) u->hw_dB_min/100.0, (double) u->hw_dB_max/100.0);
+                        u->hw_dB_supported = TRUE;
 
-                        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;
+                        if (u->hw_dB_max > 0) {
+                            u->source->base_volume = pa_sw_volume_from_dB(- (double) u->hw_dB_max/100.0);
+                            pa_log_info("Fixing base volume to %0.2f dB", pa_sw_volume_to_dB(u->source->base_volume));
+                        } else
+                            pa_log_info("No particular base volume set, fixing to 0 dB");
 
-                    } else
-                        u->hw_dB_supported = TRUE;
+                    }
                 }
 
-                if (suitable) {
-                    u->source->get_volume = source_get_volume_cb;
-                    u->source->set_volume = source_set_volume_cb;
-                    u->source->flags |= PA_SOURCE_HW_VOLUME_CTRL | (u->hw_dB_supported ? PA_SOURCE_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_capture(u->mixer_elem);
-                } else
-                    pa_log_info("Using software volume control. Leaving hw mixer controls untouched.");
+                if (!u->hw_dB_supported &&
+                    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;
+                }
             }
 
+            if (suitable) {
+                u->mixer_seperate_channels = pa_alsa_calc_mixer_map(u->mixer_elem, &map, u->mixer_map, FALSE) >= 0;
+
+                u->source->get_volume = source_get_volume_cb;
+                u->source->set_volume = source_set_volume_cb;
+                u->source->flags |= PA_SOURCE_HW_VOLUME_CTRL | (u->hw_dB_supported ? PA_SOURCE_DECIBEL_VOLUME : 0);
+                pa_log_info("Using hardware volume control. Hardware dB scale %s.", u->hw_dB_supported ? "supported" : "not supported");
+            } else
+                pa_log_info("Using software volume control.");
+        }
 
         if (snd_mixer_selem_has_capture_switch(u->mixer_elem)) {
             u->source->get_mute = source_get_mute_cb;
             u->source->set_mute = source_set_mute_cb;
             u->source->flags |= PA_SOURCE_HW_MUTE_CTRL;
-        }
+        } else
+            pa_log_info("Using software mute control.");
 
         u->mixer_fdl = pa_alsa_fdlist_new();