9 files changed, 583 insertions, 183 deletions

diff --git a/Documentation/sound/alsa/ALSA-Configuration.txt b/Documentation/sound/alsa/ALSA-Configuration.txt
index 4252697a95d6..ea16e7d184a4 100644
--- a/Documentation/sound/alsa/ALSA-Configuration.txt
+++ b/Documentation/sound/alsa/ALSA-Configuration.txt
@@ -513,6 +513,26 @@ Prior to version 0.9.0rc4 options had a 'snd_' prefix. This was removed.
     or input, but you may use this module for any application which
     requires a sound card (like RealPlayer).
 
+    pcm_devs       - Number of PCM devices assigned to each card
+                     (default = 1, up to 4)
+    pcm_substreams - Number of PCM substreams assigned to each PCM
+                     (default = 8, up to 16)
+    hrtimer        - Use hrtimer (=1, default) or system timer (=0)
+    fake_buffer    - Fake buffer allocations (default = 1)
+
+    When multiple PCM devices are created, snd-dummy gives different
+    behavior to each PCM device:
+      0 = interleaved with mmap support
+      1 = non-interleaved with mmap support
+      2 = interleaved without mmap 
+      3 = non-interleaved without mmap
+
+    As default, snd-dummy drivers doesn't allocate the real buffers
+    but either ignores read/write or mmap a single dummy page to all
+    buffer pages, in order to save the resouces.  If your apps need
+    the read/ written buffer data to be consistent, pass fake_buffer=0
+    option.
+
     The power-management is supported.
 
   Module snd-echo3g
diff --git a/include/sound/info.h b/include/sound/info.h
index 7c2ee1a21b00..112e8949e1a7 100644
--- a/include/sound/info.h
+++ b/include/sound/info.h
@@ -110,13 +110,13 @@ void snd_card_info_read_oss(struct snd_info_buffer *buffer);
 static inline void snd_card_info_read_oss(struct snd_info_buffer *buffer) {}
 #endif
 
-int snd_iprintf(struct snd_info_buffer *buffer, char *fmt, ...) \
+int snd_iprintf(struct snd_info_buffer *buffer, const char *fmt, ...) \
                                 __attribute__ ((format (printf, 2, 3)));
 int snd_info_init(void);
 int snd_info_done(void);
 
 int snd_info_get_line(struct snd_info_buffer *buffer, char *line, int len);
-char *snd_info_get_str(char *dest, char *src, int len);
+const char *snd_info_get_str(char *dest, const char *src, int len);
 struct snd_info_entry *snd_info_create_module_entry(struct module *module,
                                                const char *name,
                                                struct snd_info_entry *parent);
diff --git a/include/sound/pcm.h b/include/sound/pcm.h
index 1691c7fe35af..de6d981de5d6 100644
--- a/include/sound/pcm.h
+++ b/include/sound/pcm.h
@@ -988,4 +988,6 @@ static inline void snd_pcm_limit_isa_dma_size(int dma, size_t *max)
 
 #define PCM_RUNTIME_CHECK(sub) snd_BUG_ON(!(sub) || !(sub)->runtime)
 
+const char *snd_pcm_format_name(snd_pcm_format_t format);
+
 #endif /* __SOUND_PCM_H */
diff --git a/sound/core/info.c b/sound/core/info.c
index 3d1f5137420a..d749a0d394a7 100644
--- a/sound/core/info.c
+++ b/sound/core/info.c
@@ -106,7 +106,7 @@ static int resize_info_buffer(struct snd_info_buffer *buffer,
  *
  * Returns the size of output string.
  */
-int snd_iprintf(struct snd_info_buffer *buffer, char *fmt,...)
+int snd_iprintf(struct snd_info_buffer *buffer, const char *fmt, ...)
 {
         va_list args;
         int len, res;
@@ -725,7 +725,7 @@ EXPORT_SYMBOL(snd_info_get_line);
  * Returns the updated pointer of the original string so that
  * it can be used for the next call.
  */
-char *snd_info_get_str(char *dest, char *src, int len)
+const char *snd_info_get_str(char *dest, const char *src, int len)
 {
         int c;
 
diff --git a/sound/core/oss/mixer_oss.c b/sound/core/oss/mixer_oss.c
index 5dcd8a526970..772423889eb3 100644
--- a/sound/core/oss/mixer_oss.c
+++ b/sound/core/oss/mixer_oss.c
@@ -1154,7 +1154,8 @@ static void snd_mixer_oss_proc_write(struct snd_info_entry *entry,
                                      struct snd_info_buffer *buffer)
 {
         struct snd_mixer_oss *mixer = entry->private_data;
-        char line[128], str[32], idxstr[16], *cptr;
+        char line[128], str[32], idxstr[16];
+        const char *cptr;
         int ch, idx;
         struct snd_mixer_oss_assign_table *tbl;
         struct slot *slot;
diff --git a/sound/core/oss/pcm_oss.c b/sound/core/oss/pcm_oss.c
index dbe406b82591..d8b2d76125b4 100644
--- a/sound/core/oss/pcm_oss.c
+++ b/sound/core/oss/pcm_oss.c
@@ -2836,7 +2836,8 @@ static void snd_pcm_oss_proc_write(struct snd_info_entry *entry,
                                    struct snd_info_buffer *buffer)
 {
         struct snd_pcm_str *pstr = entry->private_data;
-        char line[128], str[32], task_name[32], *ptr;
+        char line[128], str[32], task_name[32];
+        const char *ptr;
         int idx1;
         struct snd_pcm_oss_setup *setup, *setup1, template;
 
diff --git a/sound/core/pcm.c b/sound/core/pcm.c
index 145931a9ff30..0c1440121c22 100644
--- a/sound/core/pcm.c
+++ b/sound/core/pcm.c
@@ -162,18 +162,7 @@ static int snd_pcm_control_ioctl(struct snd_card *card,
         return -ENOIOCTLCMD;
 }
 
-#ifdef CONFIG_SND_VERBOSE_PROCFS
-
-#define STATE(v) [SNDRV_PCM_STATE_##v] = #v
-#define STREAM(v) [SNDRV_PCM_STREAM_##v] = #v
-#define READY(v) [SNDRV_PCM_READY_##v] = #v
-#define XRUN(v) [SNDRV_PCM_XRUN_##v] = #v
-#define SILENCE(v) [SNDRV_PCM_SILENCE_##v] = #v
-#define TSTAMP(v) [SNDRV_PCM_TSTAMP_##v] = #v
-#define ACCESS(v) [SNDRV_PCM_ACCESS_##v] = #v
-#define START(v) [SNDRV_PCM_START_##v] = #v
 #define FORMAT(v) [SNDRV_PCM_FORMAT_##v] = #v
-#define SUBFORMAT(v) [SNDRV_PCM_SUBFORMAT_##v] = #v 
 
 static char *snd_pcm_format_names[] = {
         FORMAT(S8),
@@ -216,10 +205,23 @@ static char *snd_pcm_format_names[] = {
         FORMAT(U18_3BE),
 };
 
-static const char *snd_pcm_format_name(snd_pcm_format_t format)
+const char *snd_pcm_format_name(snd_pcm_format_t format)
 {
         return snd_pcm_format_names[format];
 }
+EXPORT_SYMBOL_GPL(snd_pcm_format_name);
+
+#ifdef CONFIG_SND_VERBOSE_PROCFS
+
+#define STATE(v) [SNDRV_PCM_STATE_##v] = #v
+#define STREAM(v) [SNDRV_PCM_STREAM_##v] = #v
+#define READY(v) [SNDRV_PCM_READY_##v] = #v
+#define XRUN(v) [SNDRV_PCM_XRUN_##v] = #v
+#define SILENCE(v) [SNDRV_PCM_SILENCE_##v] = #v
+#define TSTAMP(v) [SNDRV_PCM_TSTAMP_##v] = #v
+#define ACCESS(v) [SNDRV_PCM_ACCESS_##v] = #v
+#define START(v) [SNDRV_PCM_START_##v] = #v
+#define SUBFORMAT(v) [SNDRV_PCM_SUBFORMAT_##v] = #v 
 
 static char *snd_pcm_stream_names[] = {
         STREAM(PLAYBACK),
diff --git a/sound/drivers/dummy.c b/sound/drivers/dummy.c
index 54239d2e0997..6ba066c41d2e 100644
--- a/sound/drivers/dummy.c
+++ b/sound/drivers/dummy.c
@@ -25,12 +25,15 @@
 #include <linux/slab.h>
 #include <linux/time.h>
 #include <linux/wait.h>
+#include <linux/hrtimer.h>
+#include <linux/math64.h>
 #include <linux/moduleparam.h>
 #include <sound/core.h>
 #include <sound/control.h>
 #include <sound/tlv.h>
 #include <sound/pcm.h>
 #include <sound/rawmidi.h>
+#include <sound/info.h>
 #include <sound/initval.h>
 
 MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
@@ -39,7 +42,7 @@ MODULE_LICENSE("GPL");
 MODULE_SUPPORTED_DEVICE("{{ALSA,Dummy soundcard}}");
 
 #define MAX_PCM_DEVICES         4
-#define MAX_PCM_SUBSTREAMS      16
+#define MAX_PCM_SUBSTREAMS      128
 #define MAX_MIDI_DEVICES        2
 
 #if 0 /* emu10k1 emulation */
@@ -148,6 +151,10 @@ static int enable[SNDRV_CARDS] = {1, [1 ... (SNDRV_CARDS - 1)] = 0};
 static int pcm_devs[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 1};
 static int pcm_substreams[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 8};
 //static int midi_devs[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 2};
+#ifdef CONFIG_HIGH_RES_TIMERS
+static int hrtimer = 1;
+#endif
+static int fake_buffer = 1;
 
 module_param_array(index, int, NULL, 0444);
 MODULE_PARM_DESC(index, "Index value for dummy soundcard.");
@@ -161,6 +168,12 @@ module_param_array(pcm_substreams, int, NULL, 0444);
 MODULE_PARM_DESC(pcm_substreams, "PCM substreams # (1-16) for dummy driver.");
 //module_param_array(midi_devs, int, NULL, 0444);
 //MODULE_PARM_DESC(midi_devs, "MIDI devices # (0-2) for dummy driver.");
+module_param(fake_buffer, bool, 0444);
+MODULE_PARM_DESC(fake_buffer, "Fake buffer allocations.");
+#ifdef CONFIG_HIGH_RES_TIMERS
+module_param(hrtimer, bool, 0644);
+MODULE_PARM_DESC(hrtimer, "Use hrtimer as the timer source.");
+#endif
 
 static struct platform_device *devices[SNDRV_CARDS];
 
@@ -171,137 +184,324 @@ static struct platform_device *devices[SNDRV_CARDS];
 #define MIXER_ADDR_CD           4
 #define MIXER_ADDR_LAST         4
 
+struct dummy_timer_ops {
+        int (*create)(struct snd_pcm_substream *);
+        void (*free)(struct snd_pcm_substream *);
+        int (*prepare)(struct snd_pcm_substream *);
+        int (*start)(struct snd_pcm_substream *);
+        int (*stop)(struct snd_pcm_substream *);
+        snd_pcm_uframes_t (*pointer)(struct snd_pcm_substream *);
+};
+
 struct snd_dummy {
         struct snd_card *card;
         struct snd_pcm *pcm;
         spinlock_t mixer_lock;
         int mixer_volume[MIXER_ADDR_LAST+1][2];
         int capture_source[MIXER_ADDR_LAST+1][2];
+        const struct dummy_timer_ops *timer_ops;
 };
 
-struct snd_dummy_pcm {
-        struct snd_dummy *dummy;
+/*
+ * system timer interface
+ */
+
+struct dummy_systimer_pcm {
         spinlock_t lock;
         struct timer_list timer;
-        unsigned int pcm_buffer_size;
-        unsigned int pcm_period_size;
-        unsigned int pcm_bps;           /* bytes per second */
-        unsigned int pcm_hz;            /* HZ */
-        unsigned int pcm_irq_pos;       /* IRQ position */
-        unsigned int pcm_buf_pos;       /* position in buffer */
+        unsigned long base_time;
+        unsigned int frac_pos;  /* fractional sample position (based HZ) */
+        unsigned int frac_period_rest;
+        unsigned int frac_buffer_size;  /* buffer_size * HZ */
+        unsigned int frac_period_size;  /* period_size * HZ */
+        unsigned int rate;
+        int elapsed;
         struct snd_pcm_substream *substream;
 };
 
-
-static inline void snd_card_dummy_pcm_timer_start(struct snd_dummy_pcm *dpcm)
+static void dummy_systimer_rearm(struct dummy_systimer_pcm *dpcm)
 {
-        dpcm->timer.expires = 1 + jiffies;
+        dpcm->timer.expires = jiffies +
+                (dpcm->frac_period_rest + dpcm->rate - 1) / dpcm->rate;
         add_timer(&dpcm->timer);
 }
 
-static inline void snd_card_dummy_pcm_timer_stop(struct snd_dummy_pcm *dpcm)
+static void dummy_systimer_update(struct dummy_systimer_pcm *dpcm)
 {
-        del_timer(&dpcm->timer);
+        unsigned long delta;
+
+        delta = jiffies - dpcm->base_time;
+        if (!delta)
+                return;
+        dpcm->base_time += delta;
+        delta *= dpcm->rate;
+        dpcm->frac_pos += delta;
+        while (dpcm->frac_pos >= dpcm->frac_buffer_size)
+                dpcm->frac_pos -= dpcm->frac_buffer_size;
+        while (dpcm->frac_period_rest <= delta) {
+                dpcm->elapsed++;
+                dpcm->frac_period_rest += dpcm->frac_period_size;
+        }
+        dpcm->frac_period_rest -= delta;
 }
 
-static int snd_card_dummy_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
+static int dummy_systimer_start(struct snd_pcm_substream *substream)
 {
-        struct snd_pcm_runtime *runtime = substream->runtime;
-        struct snd_dummy_pcm *dpcm = runtime->private_data;
-        int err = 0;
+        struct dummy_systimer_pcm *dpcm = substream->runtime->private_data;
+        spin_lock(&dpcm->lock);
+        dpcm->base_time = jiffies;
+        dummy_systimer_rearm(dpcm);
+        spin_unlock(&dpcm->lock);
+        return 0;
+}
 
+static int dummy_systimer_stop(struct snd_pcm_substream *substream)
+{
+        struct dummy_systimer_pcm *dpcm = substream->runtime->private_data;
         spin_lock(&dpcm->lock);
-        switch (cmd) {
-        case SNDRV_PCM_TRIGGER_START:
-        case SNDRV_PCM_TRIGGER_RESUME:
-                snd_card_dummy_pcm_timer_start(dpcm);
-                break;
-        case SNDRV_PCM_TRIGGER_STOP:
-        case SNDRV_PCM_TRIGGER_SUSPEND:
-                snd_card_dummy_pcm_timer_stop(dpcm);
-                break;
-        default:
-                err = -EINVAL;
-                break;
-        }
+        del_timer(&dpcm->timer);
         spin_unlock(&dpcm->lock);
         return 0;
 }
 
-static int snd_card_dummy_pcm_prepare(struct snd_pcm_substream *substream)
+static int dummy_systimer_prepare(struct snd_pcm_substream *substream)
 {
         struct snd_pcm_runtime *runtime = substream->runtime;
-        struct snd_dummy_pcm *dpcm = runtime->private_data;
-        int bps;
-
-        bps = snd_pcm_format_width(runtime->format) * runtime->rate *
-                runtime->channels / 8;
-
-        if (bps <= 0)
-                return -EINVAL;
-
-        dpcm->pcm_bps = bps;
-        dpcm->pcm_hz = HZ;
-        dpcm->pcm_buffer_size = snd_pcm_lib_buffer_bytes(substream);
-        dpcm->pcm_period_size = snd_pcm_lib_period_bytes(substream);
-        dpcm->pcm_irq_pos = 0;
-        dpcm->pcm_buf_pos = 0;
+        struct dummy_systimer_pcm *dpcm = runtime->private_data;
 
-        snd_pcm_format_set_silence(runtime->format, runtime->dma_area,
-                        bytes_to_samples(runtime, runtime->dma_bytes));
+        dpcm->frac_pos = 0;
+        dpcm->rate = runtime->rate;
+        dpcm->frac_buffer_size = runtime->buffer_size * HZ;
+        dpcm->frac_period_size = runtime->period_size * HZ;
+        dpcm->frac_period_rest = dpcm->frac_period_size;
+        dpcm->elapsed = 0;
 
         return 0;
 }
 
-static void snd_card_dummy_pcm_timer_function(unsigned long data)
+static void dummy_systimer_callback(unsigned long data)
 {
-        struct snd_dummy_pcm *dpcm = (struct snd_dummy_pcm *)data;
+        struct dummy_systimer_pcm *dpcm = (struct dummy_systimer_pcm *)data;
         unsigned long flags;
+        int elapsed = 0;
         
         spin_lock_irqsave(&dpcm->lock, flags);
-        dpcm->timer.expires = 1 + jiffies;
-        add_timer(&dpcm->timer);
-        dpcm->pcm_irq_pos += dpcm->pcm_bps;
-        dpcm->pcm_buf_pos += dpcm->pcm_bps;
-        dpcm->pcm_buf_pos %= dpcm->pcm_buffer_size * dpcm->pcm_hz;
-        if (dpcm->pcm_irq_pos >= dpcm->pcm_period_size * dpcm->pcm_hz) {
-                dpcm->pcm_irq_pos %= dpcm->pcm_period_size * dpcm->pcm_hz;
-                spin_unlock_irqrestore(&dpcm->lock, flags);
+        dummy_systimer_update(dpcm);
+        dummy_systimer_rearm(dpcm);
+        elapsed = dpcm->elapsed;
+        dpcm->elapsed = 0;
+        spin_unlock_irqrestore(&dpcm->lock, flags);
+        if (elapsed)
+                snd_pcm_period_elapsed(dpcm->substream);
+}
+
+static snd_pcm_uframes_t
+dummy_systimer_pointer(struct snd_pcm_substream *substream)
+{
+        struct dummy_systimer_pcm *dpcm = substream->runtime->private_data;
+        snd_pcm_uframes_t pos;
+
+        spin_lock(&dpcm->lock);
+        dummy_systimer_update(dpcm);
+        pos = dpcm->frac_pos / HZ;
+        spin_unlock(&dpcm->lock);
+        return pos;
+}
+
+static int dummy_systimer_create(struct snd_pcm_substream *substream)
+{
+        struct dummy_systimer_pcm *dpcm;
+
+        dpcm = kzalloc(sizeof(*dpcm), GFP_KERNEL);
+        if (!dpcm)
+                return -ENOMEM;
+        substream->runtime->private_data = dpcm;
+        init_timer(&dpcm->timer);
+        dpcm->timer.data = (unsigned long) dpcm;
+        dpcm->timer.function = dummy_systimer_callback;
+        spin_lock_init(&dpcm->lock);
+        dpcm->substream = substream;
+        return 0;
+}
+
+static void dummy_systimer_free(struct snd_pcm_substream *substream)
+{
+        kfree(substream->runtime->private_data);
+}
+
+static struct dummy_timer_ops dummy_systimer_ops = {
+        .create =       dummy_systimer_create,
+        .free =         dummy_systimer_free,
+        .prepare =      dummy_systimer_prepare,
+        .start =        dummy_systimer_start,
+        .stop =         dummy_systimer_stop,
+        .pointer =      dummy_systimer_pointer,
+};
+
+#ifdef CONFIG_HIGH_RES_TIMERS
+/*
+ * hrtimer interface
+ */
+
+struct dummy_hrtimer_pcm {
+        ktime_t base_time;
+        ktime_t period_time;
+        atomic_t running;
+        struct hrtimer timer;
+        struct tasklet_struct tasklet;
+        struct snd_pcm_substream *substream;
+};
+
+static void dummy_hrtimer_pcm_elapsed(unsigned long priv)
+{
+        struct dummy_hrtimer_pcm *dpcm = (struct dummy_hrtimer_pcm *)priv;
+        if (atomic_read(&dpcm->running))
                 snd_pcm_period_elapsed(dpcm->substream);
-        } else
-                spin_unlock_irqrestore(&dpcm->lock, flags);
 }
 
-static snd_pcm_uframes_t snd_card_dummy_pcm_pointer(struct snd_pcm_substream *substream)
+static enum hrtimer_restart dummy_hrtimer_callback(struct hrtimer *timer)
+{
+        struct dummy_hrtimer_pcm *dpcm;
+
+        dpcm = container_of(timer, struct dummy_hrtimer_pcm, timer);
+        if (!atomic_read(&dpcm->running))
+                return HRTIMER_NORESTART;
+        tasklet_schedule(&dpcm->tasklet);
+        hrtimer_forward_now(timer, dpcm->period_time);
+        return HRTIMER_RESTART;
+}
+
+static int dummy_hrtimer_start(struct snd_pcm_substream *substream)
+{
+        struct dummy_hrtimer_pcm *dpcm = substream->runtime->private_data;
+
+        dpcm->base_time = hrtimer_cb_get_time(&dpcm->timer);
+        hrtimer_start(&dpcm->timer, dpcm->period_time, HRTIMER_MODE_REL);
+        atomic_set(&dpcm->running, 1);
+        return 0;
+}
+
+static int dummy_hrtimer_stop(struct snd_pcm_substream *substream)
+{
+        struct dummy_hrtimer_pcm *dpcm = substream->runtime->private_data;
+
+        atomic_set(&dpcm->running, 0);
+        hrtimer_cancel(&dpcm->timer);
+        return 0;
+}
+
+static inline void dummy_hrtimer_sync(struct dummy_hrtimer_pcm *dpcm)
+{
+        tasklet_kill(&dpcm->tasklet);
+}
+
+static snd_pcm_uframes_t
+dummy_hrtimer_pointer(struct snd_pcm_substream *substream)
 {
         struct snd_pcm_runtime *runtime = substream->runtime;
-        struct snd_dummy_pcm *dpcm = runtime->private_data;
+        struct dummy_hrtimer_pcm *dpcm = runtime->private_data;
+        u64 delta;
+        u32 pos;
+
+        delta = ktime_us_delta(hrtimer_cb_get_time(&dpcm->timer),
+                               dpcm->base_time);
+        delta = div_u64(delta * runtime->rate + 999999, 1000000);
+        div_u64_rem(delta, runtime->buffer_size, &pos);
+        return pos;
+}
 
-        return bytes_to_frames(runtime, dpcm->pcm_buf_pos / dpcm->pcm_hz);
+static int dummy_hrtimer_prepare(struct snd_pcm_substream *substream)
+{
+        struct snd_pcm_runtime *runtime = substream->runtime;
+        struct dummy_hrtimer_pcm *dpcm = runtime->private_data;
+        unsigned int period, rate;
+        long sec;
+        unsigned long nsecs;
+
+        dummy_hrtimer_sync(dpcm);
+        period = runtime->period_size;
+        rate = runtime->rate;
+        sec = period / rate;
+        period %= rate;
+        nsecs = div_u64((u64)period * 1000000000UL + rate - 1, rate);
+        dpcm->period_time = ktime_set(sec, nsecs);
+
+        return 0;
 }
 
-static struct snd_pcm_hardware snd_card_dummy_playback =
+static int dummy_hrtimer_create(struct snd_pcm_substream *substream)
 {
-        .info =                 (SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_INTERLEAVED |
-                                 SNDRV_PCM_INFO_RESUME | SNDRV_PCM_INFO_MMAP_VALID),
-        .formats =              USE_FORMATS,
-        .rates =                USE_RATE,
-        .rate_min =             USE_RATE_MIN,
-        .rate_max =             USE_RATE_MAX,
-        .channels_min =         USE_CHANNELS_MIN,
-        .channels_max =         USE_CHANNELS_MAX,
-        .buffer_bytes_max =     MAX_BUFFER_SIZE,
-        .period_bytes_min =     64,
-        .period_bytes_max =     MAX_PERIOD_SIZE,
-        .periods_min =          USE_PERIODS_MIN,
-        .periods_max =          USE_PERIODS_MAX,
-        .fifo_size =            0,
+        struct dummy_hrtimer_pcm *dpcm;
+
+        dpcm = kzalloc(sizeof(*dpcm), GFP_KERNEL);
+        if (!dpcm)
+                return -ENOMEM;
+        substream->runtime->private_data = dpcm;
+        hrtimer_init(&dpcm->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+        dpcm->timer.function = dummy_hrtimer_callback;
+        dpcm->substream = substream;
+        atomic_set(&dpcm->running, 0);
+        tasklet_init(&dpcm->tasklet, dummy_hrtimer_pcm_elapsed,
+                     (unsigned long)dpcm);
+        return 0;
+}
+
+static void dummy_hrtimer_free(struct snd_pcm_substream *substream)
+{
+        struct dummy_hrtimer_pcm *dpcm = substream->runtime->private_data;
+        dummy_hrtimer_sync(dpcm);
+        kfree(dpcm);
+}
+
+static struct dummy_timer_ops dummy_hrtimer_ops = {
+        .create =       dummy_hrtimer_create,
+        .free =         dummy_hrtimer_free,
+        .prepare =      dummy_hrtimer_prepare,
+        .start =        dummy_hrtimer_start,
+        .stop =         dummy_hrtimer_stop,
+        .pointer =      dummy_hrtimer_pointer,
 };
 
-static struct snd_pcm_hardware snd_card_dummy_capture =
+#endif /* CONFIG_HIGH_RES_TIMERS */
+
+/*
+ * PCM interface
+ */
+
+static int dummy_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
 {
-        .info =                 (SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_INTERLEAVED |
-                                 SNDRV_PCM_INFO_RESUME | SNDRV_PCM_INFO_MMAP_VALID),
+        struct snd_dummy *dummy = snd_pcm_substream_chip(substream);
+
+        switch (cmd) {
+        case SNDRV_PCM_TRIGGER_START:
+        case SNDRV_PCM_TRIGGER_RESUME:
+                return dummy->timer_ops->start(substream);
+        case SNDRV_PCM_TRIGGER_STOP:
+        case SNDRV_PCM_TRIGGER_SUSPEND:
+                return dummy->timer_ops->stop(substream);
+        }
+        return -EINVAL;
+}
+
+static int dummy_pcm_prepare(struct snd_pcm_substream *substream)
+{
+        struct snd_dummy *dummy = snd_pcm_substream_chip(substream);
+
+        return dummy->timer_ops->prepare(substream);
+}
+
+static snd_pcm_uframes_t dummy_pcm_pointer(struct snd_pcm_substream *substream)
+{
+        struct snd_dummy *dummy = snd_pcm_substream_chip(substream);
+
+        return dummy->timer_ops->pointer(substream);
+}
+
+static struct snd_pcm_hardware dummy_pcm_hardware = {
+        .info =                 (SNDRV_PCM_INFO_MMAP |
+                                 SNDRV_PCM_INFO_INTERLEAVED |
+                                 SNDRV_PCM_INFO_RESUME |
+                                 SNDRV_PCM_INFO_MMAP_VALID),
         .formats =              USE_FORMATS,
         .rates =                USE_RATE,
         .rate_min =             USE_RATE_MIN,
@@ -316,123 +516,152 @@ static struct snd_pcm_hardware snd_card_dummy_capture =
         .fifo_size =            0,
 };
 
-static void snd_card_dummy_runtime_free(struct snd_pcm_runtime *runtime)
-{
-        kfree(runtime->private_data);
-}
-
-static int snd_card_dummy_hw_params(struct snd_pcm_substream *substream,
-                                    struct snd_pcm_hw_params *hw_params)
+static int dummy_pcm_hw_params(struct snd_pcm_substream *substream,
+                               struct snd_pcm_hw_params *hw_params)
 {
-        return snd_pcm_lib_malloc_pages(substream, params_buffer_bytes(hw_params));
+        if (fake_buffer) {
+                /* runtime->dma_bytes has to be set manually to allow mmap */
+                substream->runtime->dma_bytes = params_buffer_bytes(hw_params);
+                return 0;
+        }
+        return snd_pcm_lib_malloc_pages(substream,
+                                        params_buffer_bytes(hw_params));
 }
 
-static int snd_card_dummy_hw_free(struct snd_pcm_substream *substream)
+static int dummy_pcm_hw_free(struct snd_pcm_substream *substream)
 {
+        if (fake_buffer)
+                return 0;
         return snd_pcm_lib_free_pages(substream);
 }
 
-static struct snd_dummy_pcm *new_pcm_stream(struct snd_pcm_substream *substream)
-{
-        struct snd_dummy_pcm *dpcm;
-
-        dpcm = kzalloc(sizeof(*dpcm), GFP_KERNEL);
-        if (! dpcm)
-                return dpcm;
-        init_timer(&dpcm->timer);
-        dpcm->timer.data = (unsigned long) dpcm;
-        dpcm->timer.function = snd_card_dummy_pcm_timer_function;
-        spin_lock_init(&dpcm->lock);
-        dpcm->substream = substream;
-        return dpcm;
-}
-
-static int snd_card_dummy_playback_open(struct snd_pcm_substream *substream)
+static int dummy_pcm_open(struct snd_pcm_substream *substream)
 {
+        struct snd_dummy *dummy = snd_pcm_substream_chip(substream);
         struct snd_pcm_runtime *runtime = substream->runtime;
-        struct snd_dummy_pcm *dpcm;
         int err;
 
-        if ((dpcm = new_pcm_stream(substream)) == NULL)
-                return -ENOMEM;
-        runtime->private_data = dpcm;
-        /* makes the infrastructure responsible for freeing dpcm */
-        runtime->private_free = snd_card_dummy_runtime_free;
-        runtime->hw = snd_card_dummy_playback;
+        dummy->timer_ops = &dummy_systimer_ops;
+#ifdef CONFIG_HIGH_RES_TIMERS
+        if (hrtimer)
+                dummy->timer_ops = &dummy_hrtimer_ops;
+#endif
+
+        err = dummy->timer_ops->create(substream);
+        if (err < 0)
+                return err;
+
+        runtime->hw = dummy_pcm_hardware;
         if (substream->pcm->device & 1) {
                 runtime->hw.info &= ~SNDRV_PCM_INFO_INTERLEAVED;
                 runtime->hw.info |= SNDRV_PCM_INFO_NONINTERLEAVED;
         }
         if (substream->pcm->device & 2)
-                runtime->hw.info &= ~(SNDRV_PCM_INFO_MMAP|SNDRV_PCM_INFO_MMAP_VALID);
-        err = add_playback_constraints(runtime);
-        if (err < 0)
+                runtime->hw.info &= ~(SNDRV_PCM_INFO_MMAP |
+                                      SNDRV_PCM_INFO_MMAP_VALID);
+
+        if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
+                err = add_playback_constraints(substream->runtime);
+        else
+                err = add_capture_constraints(substream->runtime);
+        if (err < 0) {
+                dummy->timer_ops->free(substream);
                 return err;
-
+        }
         return 0;
 }
 
-static int snd_card_dummy_capture_open(struct snd_pcm_substream *substream)
+static int dummy_pcm_close(struct snd_pcm_substream *substream)
 {
-        struct snd_pcm_runtime *runtime = substream->runtime;
-        struct snd_dummy_pcm *dpcm;
-        int err;
+        struct snd_dummy *dummy = snd_pcm_substream_chip(substream);
+        dummy->timer_ops->free(substream);
+        return 0;
+}
 
-        if ((dpcm = new_pcm_stream(substream)) == NULL)
-                return -ENOMEM;
-        runtime->private_data = dpcm;
-        /* makes the infrastructure responsible for freeing dpcm */
-        runtime->private_free = snd_card_dummy_runtime_free;
-        runtime->hw = snd_card_dummy_capture;
-        if (substream->pcm->device == 1) {
-                runtime->hw.info &= ~SNDRV_PCM_INFO_INTERLEAVED;
-                runtime->hw.info |= SNDRV_PCM_INFO_NONINTERLEAVED;
+/*
+ * dummy buffer handling
+ */
+
+static void *dummy_page[2];
+
+static void free_fake_buffer(void)
+{
+        if (fake_buffer) {
+                int i;
+                for (i = 0; i < 2; i++)
+                        if (dummy_page[i]) {
+                                free_page((unsigned long)dummy_page[i]);
+                                dummy_page[i] = NULL;
+                        }
         }
-        if (substream->pcm->device & 2)
-                runtime->hw.info &= ~(SNDRV_PCM_INFO_MMAP|SNDRV_PCM_INFO_MMAP_VALID);
-        err = add_capture_constraints(runtime);
-        if (err < 0)
-                return err;
+}
 
+static int alloc_fake_buffer(void)
+{
+        int i;
+
+        if (!fake_buffer)
+                return 0;
+        for (i = 0; i < 2; i++) {
+                dummy_page[i] = (void *)get_zeroed_page(GFP_KERNEL);
+                if (!dummy_page[i]) {
+                        free_fake_buffer();
+                        return -ENOMEM;
+                }
+        }
         return 0;
 }
 
-static int snd_card_dummy_playback_close(struct snd_pcm_substream *substream)
+static int dummy_pcm_copy(struct snd_pcm_substream *substream,
+                          int channel, snd_pcm_uframes_t pos,
+                          void __user *dst, snd_pcm_uframes_t count)
 {
-        return 0;
+        return 0; /* do nothing */
 }
 
-static int snd_card_dummy_capture_close(struct snd_pcm_substream *substream)
+static int dummy_pcm_silence(struct snd_pcm_substream *substream,
+                             int channel, snd_pcm_uframes_t pos,
+                             snd_pcm_uframes_t count)
 {
-        return 0;
+        return 0; /* do nothing */
+}
+
+static struct page *dummy_pcm_page(struct snd_pcm_substream *substream,
+                                   unsigned long offset)
+{
+        return virt_to_page(dummy_page[substream->stream]); /* the same page */
 }
 
-static struct snd_pcm_ops snd_card_dummy_playback_ops = {
-        .open =                 snd_card_dummy_playback_open,
-        .close =                snd_card_dummy_playback_close,
-        .ioctl =                snd_pcm_lib_ioctl,
-        .hw_params =            snd_card_dummy_hw_params,
-        .hw_free =              snd_card_dummy_hw_free,
-        .prepare =              snd_card_dummy_pcm_prepare,
-        .trigger =              snd_card_dummy_pcm_trigger,
-        .pointer =              snd_card_dummy_pcm_pointer,
+static struct snd_pcm_ops dummy_pcm_ops = {
+        .open =         dummy_pcm_open,
+        .close =        dummy_pcm_close,
+        .ioctl =        snd_pcm_lib_ioctl,
+        .hw_params =    dummy_pcm_hw_params,
+        .hw_free =      dummy_pcm_hw_free,
+        .prepare =      dummy_pcm_prepare,
+        .trigger =      dummy_pcm_trigger,
+        .pointer =      dummy_pcm_pointer,
 };
 
-static struct snd_pcm_ops snd_card_dummy_capture_ops = {
-        .open =                 snd_card_dummy_capture_open,
-        .close =                snd_card_dummy_capture_close,
-        .ioctl =                snd_pcm_lib_ioctl,
-        .hw_params =            snd_card_dummy_hw_params,
-        .hw_free =              snd_card_dummy_hw_free,
-        .prepare =              snd_card_dummy_pcm_prepare,
-        .trigger =              snd_card_dummy_pcm_trigger,
-        .pointer =              snd_card_dummy_pcm_pointer,
+static struct snd_pcm_ops dummy_pcm_ops_no_buf = {
+        .open =         dummy_pcm_open,
+        .close =        dummy_pcm_close,
+        .ioctl =        snd_pcm_lib_ioctl,
+        .hw_params =    dummy_pcm_hw_params,
+        .hw_free =      dummy_pcm_hw_free,
+        .prepare =      dummy_pcm_prepare,
+        .trigger =      dummy_pcm_trigger,
+        .pointer =      dummy_pcm_pointer,
+        .copy =         dummy_pcm_copy,
+        .silence =      dummy_pcm_silence,
+        .page =         dummy_pcm_page,
 };
 
 static int __devinit snd_card_dummy_pcm(struct snd_dummy *dummy, int device,
                                         int substreams)
 {
         struct snd_pcm *pcm;
+        struct snd_pcm_ops *ops;
         int err;
 
         err = snd_pcm_new(dummy->card, "Dummy PCM", device,
@@ -440,17 +669,28 @@ static int __devinit snd_card_dummy_pcm(struct snd_dummy *dummy, int device,
         if (err < 0)
                 return err;
         dummy->pcm = pcm;
-        snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &snd_card_dummy_playback_ops);
-        snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &snd_card_dummy_capture_ops);
+        if (fake_buffer)
+                ops = &dummy_pcm_ops_no_buf;
+        else
+                ops = &dummy_pcm_ops;
+        snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, ops);
+        snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, ops);
         pcm->private_data = dummy;
         pcm->info_flags = 0;
         strcpy(pcm->name, "Dummy PCM");
-        snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_CONTINUOUS,
-                                              snd_dma_continuous_data(GFP_KERNEL),
-                                              0, 64*1024);
+        if (!fake_buffer) {
+                snd_pcm_lib_preallocate_pages_for_all(pcm,
+                        SNDRV_DMA_TYPE_CONTINUOUS,
+                        snd_dma_continuous_data(GFP_KERNEL),
+                        0, 64*1024);
+        }
         return 0;
 }
 
+/*
+ * mixer interface
+ */
+
 #define DUMMY_VOLUME(xname, xindex, addr) \
 { .iface = SNDRV_CTL_ELEM_IFACE_MIXER, \
   .access = SNDRV_CTL_ELEM_ACCESS_READWRITE | SNDRV_CTL_ELEM_ACCESS_TLV_READ, \
@@ -581,6 +821,131 @@ static int __devinit snd_card_dummy_new_mixer(struct snd_dummy *dummy)
         return 0;
 }
 
+#if defined(CONFIG_SND_DEBUG) && defined(CONFIG_PROC_FS)
+/*
+ * proc interface
+ */
+static void print_formats(struct snd_info_buffer *buffer)
+{
+        int i;
+
+        for (i = 0; i < SNDRV_PCM_FORMAT_LAST; i++) {
+                if (dummy_pcm_hardware.formats & (1ULL << i))
+                        snd_iprintf(buffer, " %s", snd_pcm_format_name(i));
+        }
+}
+
+static void print_rates(struct snd_info_buffer *buffer)
+{
+        static int rates[] = {
+                5512, 8000, 11025, 16000, 22050, 32000, 44100, 48000,
+                64000, 88200, 96000, 176400, 192000,
+        };
+        int i;
+
+        if (dummy_pcm_hardware.rates & SNDRV_PCM_RATE_CONTINUOUS)
+                snd_iprintf(buffer, " continuous");
+        if (dummy_pcm_hardware.rates & SNDRV_PCM_RATE_KNOT)
+                snd_iprintf(buffer, " knot");
+        for (i = 0; i < ARRAY_SIZE(rates); i++)
+                if (dummy_pcm_hardware.rates & (1 << i))
+                        snd_iprintf(buffer, " %d", rates[i]);
+}
+
+#define get_dummy_int_ptr(ofs) \
+        (unsigned int *)((char *)&dummy_pcm_hardware + (ofs))
+#define get_dummy_ll_ptr(ofs) \
+        (unsigned long long *)((char *)&dummy_pcm_hardware + (ofs))
+
+struct dummy_hw_field {
+        const char *name;
+        const char *format;
+        unsigned int offset;
+        unsigned int size;
+};
+#define FIELD_ENTRY(item, fmt) {                   \
+        .name = #item,                             \
+        .format = fmt,                             \
+        .offset = offsetof(struct snd_pcm_hardware, item), \
+        .size = sizeof(dummy_pcm_hardware.item) }
+
+static struct dummy_hw_field fields[] = {
+        FIELD_ENTRY(formats, "%#llx"),
+        FIELD_ENTRY(rates, "%#x"),
+        FIELD_ENTRY(rate_min, "%d"),
+        FIELD_ENTRY(rate_max, "%d"),
+        FIELD_ENTRY(channels_min, "%d"),
+        FIELD_ENTRY(channels_max, "%d"),
+        FIELD_ENTRY(buffer_bytes_max, "%ld"),
+        FIELD_ENTRY(period_bytes_min, "%ld"),
+        FIELD_ENTRY(period_bytes_max, "%ld"),
+        FIELD_ENTRY(periods_min, "%d"),
+        FIELD_ENTRY(periods_max, "%d"),
+};
+
+static void dummy_proc_read(struct snd_info_entry *entry,
+                            struct snd_info_buffer *buffer)
+{
+        int i;
+
+        for (i = 0; i < ARRAY_SIZE(fields); i++) {
+                snd_iprintf(buffer, "%s ", fields[i].name);
+                if (fields[i].size == sizeof(int))
+                        snd_iprintf(buffer, fields[i].format,
+                                    *get_dummy_int_ptr(fields[i].offset));
+                else
+                        snd_iprintf(buffer, fields[i].format,
+                                    *get_dummy_ll_ptr(fields[i].offset));
+                if (!strcmp(fields[i].name, "formats"))
+                        print_formats(buffer);
+                else if (!strcmp(fields[i].name, "rates"))
+                        print_rates(buffer);
+                snd_iprintf(buffer, "\n");
+        }
+}
+
+static void dummy_proc_write(struct snd_info_entry *entry,
+                             struct snd_info_buffer *buffer)
+{
+        char line[64];
+
+        while (!snd_info_get_line(buffer, line, sizeof(line))) {
+                char item[20];
+                const char *ptr;
+                unsigned long long val;
+                int i;
+
+                ptr = snd_info_get_str(item, line, sizeof(item));
+                for (i = 0; i < ARRAY_SIZE(fields); i++) {
+                        if (!strcmp(item, fields[i].name))
+                                break;
+                }
+                if (i >= ARRAY_SIZE(fields))
+                        continue;
+                snd_info_get_str(item, ptr, sizeof(item));
+                if (strict_strtoull(item, 0, &val))
+                        continue;
+                if (fields[i].size == sizeof(int))
+                        *get_dummy_int_ptr(fields[i].offset) = val;
+                else
+                        *get_dummy_ll_ptr(fields[i].offset) = val;
+        }
+}
+
+static void __devinit dummy_proc_init(struct snd_dummy *chip)
+{
+        struct snd_info_entry *entry;
+
+        if (!snd_card_proc_new(chip->card, "dummy_pcm", &entry)) {
+                snd_info_set_text_ops(entry, chip, dummy_proc_read);
+                entry->c.text.write = dummy_proc_write;
+                entry->mode |= S_IWUSR;
+        }
+}
+#else
+#define dummy_proc_init(x)
+#endif /* CONFIG_SND_DEBUG && CONFIG_PROC_FS */
+
 static int __devinit snd_dummy_probe(struct platform_device *devptr)
 {
         struct snd_card *card;
@@ -610,6 +975,8 @@ static int __devinit snd_dummy_probe(struct platform_device *devptr)
         strcpy(card->shortname, "Dummy");
         sprintf(card->longname, "Dummy %i", dev + 1);
 
+        dummy_proc_init(dummy);
+
         snd_card_set_dev(card, &devptr->dev);
 
         err = snd_card_register(card);
@@ -670,6 +1037,7 @@ static void snd_dummy_unregister_all(void)
         for (i = 0; i < ARRAY_SIZE(devices); ++i)
                 platform_device_unregister(devices[i]);
         platform_driver_unregister(&snd_dummy_driver);
+        free_fake_buffer();
 }
 
 static int __init alsa_card_dummy_init(void)
@@ -680,6 +1048,12 @@ static int __init alsa_card_dummy_init(void)
         if (err < 0)
                 return err;
 
+        err = alloc_fake_buffer();
+        if (err < 0) {
+                platform_driver_unregister(&snd_dummy_driver);
+                return err;
+        }
+
         cards = 0;
         for (i = 0; i < SNDRV_CARDS; i++) {
                 struct platform_device *device;
diff --git a/sound/usb/usbaudio.c b/sound/usb/usbaudio.c
index 44b9cdc8a83b..3a53c79f48b8 100644
--- a/sound/usb/usbaudio.c
+++ b/sound/usb/usbaudio.c
@@ -2124,8 +2124,8 @@ static void proc_dump_substream_formats(struct snd_usb_substream *subs, struct s
                 fp = list_entry(p, struct audioformat, list);
                 snd_iprintf(buffer, "  Interface %d\n", fp->iface);
                 snd_iprintf(buffer, "    Altset %d\n", fp->altsetting);
-                snd_iprintf(buffer, "    Format: %#x (%d bits)\n",
-                            fp->format, snd_pcm_format_width(fp->format));
+                snd_iprintf(buffer, "    Format: %s\n",
+                            snd_pcm_format_name(fp->format));
                 snd_iprintf(buffer, "    Channels: %d\n", fp->channels);
                 snd_iprintf(buffer, "    Endpoint: %d %s (%s)\n",
                             fp->endpoint & USB_ENDPOINT_NUMBER_MASK,