7 files changed, 476 insertions, 86 deletions
diff --git a/sound/core/pcm.c b/sound/core/pcm.c
index 290690fc2abc..283aac441fa0 100644
--- a/sound/core/pcm.c
+++ b/sound/core/pcm.c
@@ -592,7 +592,6 @@ static const struct attribute_group *pcm_dev_attr_groups[];
  * PM callbacks: we need to deal only with suspend here, as the resume is
  * triggered either from user-space or the driver's resume callback
  */
-#ifdef CONFIG_PM_SLEEP
 static int do_pcm_suspend(struct device *dev)
 {
 	struct snd_pcm_str *pstr = dev_get_drvdata(dev);
@@ -601,10 +600,9 @@ static int do_pcm_suspend(struct device *dev)
 		snd_pcm_suspend_all(pstr->pcm);
 	return 0;
 }
-#endif
 
 static const struct dev_pm_ops pcm_dev_pm_ops = {
-	SET_SYSTEM_SLEEP_PM_OPS(do_pcm_suspend, NULL)
+	SYSTEM_SLEEP_PM_OPS(do_pcm_suspend, NULL)
 };
 
 /* device type for PCM -- basically only for passing PM callbacks */
diff --git a/sound/core/pcm_drm_eld.c b/sound/core/pcm_drm_eld.c
index 1cdca4d4fc9c..688eefce82fa 100644
--- a/sound/core/pcm_drm_eld.c
+++ b/sound/core/pcm_drm_eld.c
@@ -5,8 +5,10 @@
 #include <linux/bitfield.h>
 #include <linux/export.h>
 #include <linux/hdmi.h>
+#include <linux/unaligned.h>
 #include <drm/drm_edid.h>
 #include <drm/drm_eld.h>
+#include <sound/info.h>
 #include <sound/pcm.h>
 #include <sound/pcm_drm_eld.h>
 
@@ -162,3 +164,388 @@ int snd_pcm_hw_constraint_eld(struct snd_pcm_runtime *runtime, void *eld)
 	return ret;
 }
 EXPORT_SYMBOL_GPL(snd_pcm_hw_constraint_eld);
+
+#define SND_PRINT_RATES_ADVISED_BUFSIZE	80
+#define SND_PRINT_BITS_ADVISED_BUFSIZE	16
+#define SND_PRINT_CHANNEL_ALLOCATION_ADVISED_BUFSIZE 80
+
+static const char * const eld_connection_type_names[4] = {
+	"HDMI",
+	"DisplayPort",
+	"2-reserved",
+	"3-reserved"
+};
+
+static const char * const cea_audio_coding_type_names[] = {
+	/*  0 */ "undefined",
+	/*  1 */ "LPCM",
+	/*  2 */ "AC-3",
+	/*  3 */ "MPEG1",
+	/*  4 */ "MP3",
+	/*  5 */ "MPEG2",
+	/*  6 */ "AAC-LC",
+	/*  7 */ "DTS",
+	/*  8 */ "ATRAC",
+	/*  9 */ "DSD (One Bit Audio)",
+	/* 10 */ "E-AC-3/DD+ (Dolby Digital Plus)",
+	/* 11 */ "DTS-HD",
+	/* 12 */ "MLP (Dolby TrueHD)",
+	/* 13 */ "DST",
+	/* 14 */ "WMAPro",
+	/* 15 */ "HE-AAC",
+	/* 16 */ "HE-AACv2",
+	/* 17 */ "MPEG Surround",
+};
+
+static const char * const cea_speaker_allocation_names[] = {
+	/*  0 */ "FL/FR",
+	/*  1 */ "LFE",
+	/*  2 */ "FC",
+	/*  3 */ "RL/RR",
+	/*  4 */ "RC",
+	/*  5 */ "FLC/FRC",
+	/*  6 */ "RLC/RRC",
+	/*  7 */ "FLW/FRW",
+	/*  8 */ "FLH/FRH",
+	/*  9 */ "TC",
+	/* 10 */ "FCH",
+};
+
+/*
+ * SS1:SS0 index => sample size
+ */
+static const int cea_sample_sizes[4] = {
+	0,			/* 0: Refer to Stream Header */
+	ELD_PCM_BITS_16,	/* 1: 16 bits */
+	ELD_PCM_BITS_20,	/* 2: 20 bits */
+	ELD_PCM_BITS_24,	/* 3: 24 bits */
+};
+
+/*
+ * SF2:SF1:SF0 index => sampling frequency
+ */
+static const int cea_sampling_frequencies[8] = {
+	0,			/* 0: Refer to Stream Header */
+	SNDRV_PCM_RATE_32000,	/* 1:  32000Hz */
+	SNDRV_PCM_RATE_44100,	/* 2:  44100Hz */
+	SNDRV_PCM_RATE_48000,	/* 3:  48000Hz */
+	SNDRV_PCM_RATE_88200,	/* 4:  88200Hz */
+	SNDRV_PCM_RATE_96000,	/* 5:  96000Hz */
+	SNDRV_PCM_RATE_176400,	/* 6: 176400Hz */
+	SNDRV_PCM_RATE_192000,	/* 7: 192000Hz */
+};
+
+#define GRAB_BITS(buf, byte, lowbit, bits)		\
+({							\
+	BUILD_BUG_ON(lowbit > 7);			\
+	BUILD_BUG_ON(bits > 8);				\
+	BUILD_BUG_ON(bits <= 0);			\
+							\
+	(buf[byte] >> (lowbit)) & ((1 << (bits)) - 1);	\
+})
+
+static void hdmi_update_short_audio_desc(struct device *dev,
+					 struct snd_cea_sad *a,
+					 const unsigned char *buf)
+{
+	int i;
+	int val;
+
+	val = GRAB_BITS(buf, 1, 0, 7);
+	a->rates = 0;
+	for (i = 0; i < 7; i++)
+		if (val & (1 << i))
+			a->rates |= cea_sampling_frequencies[i + 1];
+
+	a->channels = GRAB_BITS(buf, 0, 0, 3);
+	a->channels++;
+
+	a->sample_bits = 0;
+	a->max_bitrate = 0;
+
+	a->format = GRAB_BITS(buf, 0, 3, 4);
+	switch (a->format) {
+	case AUDIO_CODING_TYPE_REF_STREAM_HEADER:
+		dev_info(dev, "HDMI: audio coding type 0 not expected\n");
+		break;
+
+	case AUDIO_CODING_TYPE_LPCM:
+		val = GRAB_BITS(buf, 2, 0, 3);
+		for (i = 0; i < 3; i++)
+			if (val & (1 << i))
+				a->sample_bits |= cea_sample_sizes[i + 1];
+		break;
+
+	case AUDIO_CODING_TYPE_AC3:
+	case AUDIO_CODING_TYPE_MPEG1:
+	case AUDIO_CODING_TYPE_MP3:
+	case AUDIO_CODING_TYPE_MPEG2:
+	case AUDIO_CODING_TYPE_AACLC:
+	case AUDIO_CODING_TYPE_DTS:
+	case AUDIO_CODING_TYPE_ATRAC:
+		a->max_bitrate = GRAB_BITS(buf, 2, 0, 8);
+		a->max_bitrate *= 8000;
+		break;
+
+	case AUDIO_CODING_TYPE_SACD:
+		break;
+
+	case AUDIO_CODING_TYPE_EAC3:
+		break;
+
+	case AUDIO_CODING_TYPE_DTS_HD:
+		break;
+
+	case AUDIO_CODING_TYPE_MLP:
+		break;
+
+	case AUDIO_CODING_TYPE_DST:
+		break;
+
+	case AUDIO_CODING_TYPE_WMAPRO:
+		a->profile = GRAB_BITS(buf, 2, 0, 3);
+		break;
+
+	case AUDIO_CODING_TYPE_REF_CXT:
+		a->format = GRAB_BITS(buf, 2, 3, 5);
+		if (a->format == AUDIO_CODING_XTYPE_HE_REF_CT ||
+		    a->format >= AUDIO_CODING_XTYPE_FIRST_RESERVED) {
+			dev_info(dev,
+				   "HDMI: audio coding xtype %d not expected\n",
+				   a->format);
+			a->format = 0;
+		} else
+			a->format += AUDIO_CODING_TYPE_HE_AAC -
+				     AUDIO_CODING_XTYPE_HE_AAC;
+		break;
+	}
+}
+
+/*
+ * Be careful, ELD buf could be totally rubbish!
+ */
+int snd_parse_eld(struct device *dev, struct snd_parsed_hdmi_eld *e,
+		  const unsigned char *buf, int size)
+{
+	int mnl;
+	int i;
+
+	memset(e, 0, sizeof(*e));
+	e->eld_ver = GRAB_BITS(buf, 0, 3, 5);
+	if (e->eld_ver != ELD_VER_CEA_861D &&
+	    e->eld_ver != ELD_VER_PARTIAL) {
+		dev_info(dev, "HDMI: Unknown ELD version %d\n", e->eld_ver);
+		goto out_fail;
+	}
+
+	e->baseline_len = GRAB_BITS(buf, 2, 0, 8);
+	mnl		= GRAB_BITS(buf, 4, 0, 5);
+	e->cea_edid_ver	= GRAB_BITS(buf, 4, 5, 3);
+
+	e->support_hdcp	= GRAB_BITS(buf, 5, 0, 1);
+	e->support_ai	= GRAB_BITS(buf, 5, 1, 1);
+	e->conn_type	= GRAB_BITS(buf, 5, 2, 2);
+	e->sad_count	= GRAB_BITS(buf, 5, 4, 4);
+
+	e->aud_synch_delay = GRAB_BITS(buf, 6, 0, 8) * 2;
+	e->spk_alloc	= GRAB_BITS(buf, 7, 0, 7);
+
+	e->port_id	  = get_unaligned_le64(buf + 8);
+
+	/* not specified, but the spec's tendency is little endian */
+	e->manufacture_id = get_unaligned_le16(buf + 16);
+	e->product_id	  = get_unaligned_le16(buf + 18);
+
+	if (mnl > ELD_MAX_MNL) {
+		dev_info(dev, "HDMI: MNL is reserved value %d\n", mnl);
+		goto out_fail;
+	} else if (ELD_FIXED_BYTES + mnl > size) {
+		dev_info(dev, "HDMI: out of range MNL %d\n", mnl);
+		goto out_fail;
+	} else
+		strscpy(e->monitor_name, buf + ELD_FIXED_BYTES, mnl + 1);
+
+	for (i = 0; i < e->sad_count; i++) {
+		if (ELD_FIXED_BYTES + mnl + 3 * (i + 1) > size) {
+			dev_info(dev, "HDMI: out of range SAD %d\n", i);
+			goto out_fail;
+		}
+		hdmi_update_short_audio_desc(dev, e->sad + i,
+					     buf + ELD_FIXED_BYTES + mnl + 3 * i);
+	}
+
+	/*
+	 * HDMI sink's ELD info cannot always be retrieved for now, e.g.
+	 * in console or for audio devices. Assume the highest speakers
+	 * configuration, to _not_ prohibit multi-channel audio playback.
+	 */
+	if (!e->spk_alloc)
+		e->spk_alloc = 0xffff;
+
+	return 0;
+
+out_fail:
+	return -EINVAL;
+}
+EXPORT_SYMBOL_GPL(snd_parse_eld);
+
+/*
+ * SNDRV_PCM_RATE_* and AC_PAR_PCM values don't match, print correct rates with
+ * hdmi-specific routine.
+ */
+static void hdmi_print_pcm_rates(int pcm, char *buf, int buflen)
+{
+	static const unsigned int alsa_rates[] = {
+		5512, 8000, 11025, 16000, 22050, 32000, 44100, 48000, 64000,
+		88200, 96000, 176400, 192000, 384000
+	};
+	int i, j;
+
+	for (i = 0, j = 0; i < ARRAY_SIZE(alsa_rates); i++)
+		if (pcm & (1 << i))
+			j += scnprintf(buf + j, buflen - j,  " %d",
+				alsa_rates[i]);
+
+	buf[j] = '\0'; /* necessary when j == 0 */
+}
+
+static void eld_print_pcm_bits(int pcm, char *buf, int buflen)
+{
+	static const unsigned int bits[] = { 8, 16, 20, 24, 32 };
+	int i, j;
+
+	for (i = 0, j = 0; i < ARRAY_SIZE(bits); i++)
+		if (pcm & (ELD_PCM_BITS_8 << i))
+			j += scnprintf(buf + j, buflen - j,  " %d", bits[i]);
+
+	buf[j] = '\0'; /* necessary when j == 0 */
+}
+
+static void hdmi_show_short_audio_desc(struct device *dev,
+				       struct snd_cea_sad *a)
+{
+	char buf[SND_PRINT_RATES_ADVISED_BUFSIZE];
+	char buf2[8 + SND_PRINT_BITS_ADVISED_BUFSIZE] = ", bits =";
+
+	if (!a->format)
+		return;
+
+	hdmi_print_pcm_rates(a->rates, buf, sizeof(buf));
+
+	if (a->format == AUDIO_CODING_TYPE_LPCM)
+		eld_print_pcm_bits(a->sample_bits, buf2 + 8, sizeof(buf2) - 8);
+	else if (a->max_bitrate)
+		snprintf(buf2, sizeof(buf2),
+				", max bitrate = %d", a->max_bitrate);
+	else
+		buf2[0] = '\0';
+
+	dev_dbg(dev,
+		"HDMI: supports coding type %s: channels = %d, rates =%s%s\n",
+		cea_audio_coding_type_names[a->format],
+		a->channels, buf, buf2);
+}
+
+static void snd_eld_print_channel_allocation(int spk_alloc, char *buf, int buflen)
+{
+	int i, j;
+
+	for (i = 0, j = 0; i < ARRAY_SIZE(cea_speaker_allocation_names); i++) {
+		if (spk_alloc & (1 << i))
+			j += scnprintf(buf + j, buflen - j,  " %s",
+					cea_speaker_allocation_names[i]);
+	}
+	buf[j] = '\0';	/* necessary when j == 0 */
+}
+
+void snd_show_eld(struct device *dev, struct snd_parsed_hdmi_eld *e)
+{
+	int i;
+
+	dev_dbg(dev, "HDMI: detected monitor %s at connection type %s\n",
+		e->monitor_name,
+		eld_connection_type_names[e->conn_type]);
+
+	if (e->spk_alloc) {
+		char buf[SND_PRINT_CHANNEL_ALLOCATION_ADVISED_BUFSIZE];
+
+		snd_eld_print_channel_allocation(e->spk_alloc, buf, sizeof(buf));
+		dev_dbg(dev, "HDMI: available speakers:%s\n", buf);
+	}
+
+	for (i = 0; i < e->sad_count; i++)
+		hdmi_show_short_audio_desc(dev, e->sad + i);
+}
+EXPORT_SYMBOL_GPL(snd_show_eld);
+
+#ifdef CONFIG_SND_PROC_FS
+static void hdmi_print_sad_info(int i, struct snd_cea_sad *a,
+				struct snd_info_buffer *buffer)
+{
+	char buf[SND_PRINT_RATES_ADVISED_BUFSIZE];
+
+	snd_iprintf(buffer, "sad%d_coding_type\t[0x%x] %s\n",
+			i, a->format, cea_audio_coding_type_names[a->format]);
+	snd_iprintf(buffer, "sad%d_channels\t\t%d\n", i, a->channels);
+
+	hdmi_print_pcm_rates(a->rates, buf, sizeof(buf));
+	snd_iprintf(buffer, "sad%d_rates\t\t[0x%x]%s\n", i, a->rates, buf);
+
+	if (a->format == AUDIO_CODING_TYPE_LPCM) {
+		eld_print_pcm_bits(a->sample_bits, buf, sizeof(buf));
+		snd_iprintf(buffer, "sad%d_bits\t\t[0x%x]%s\n",
+							i, a->sample_bits, buf);
+	}
+
+	if (a->max_bitrate)
+		snd_iprintf(buffer, "sad%d_max_bitrate\t%d\n",
+							i, a->max_bitrate);
+
+	if (a->profile)
+		snd_iprintf(buffer, "sad%d_profile\t\t%d\n", i, a->profile);
+}
+
+void snd_print_eld_info(struct snd_parsed_hdmi_eld *e,
+			struct snd_info_buffer *buffer)
+{
+	char buf[SND_PRINT_CHANNEL_ALLOCATION_ADVISED_BUFSIZE];
+	int i;
+	static const char * const eld_version_names[32] = {
+		"reserved",
+		"reserved",
+		"CEA-861D or below",
+		[3 ... 30] = "reserved",
+		[31] = "partial"
+	};
+	static const char * const cea_edid_version_names[8] = {
+		"no CEA EDID Timing Extension block present",
+		"CEA-861",
+		"CEA-861-A",
+		"CEA-861-B, C or D",
+		[4 ... 7] = "reserved"
+	};
+
+	snd_iprintf(buffer, "monitor_name\t\t%s\n", e->monitor_name);
+	snd_iprintf(buffer, "connection_type\t\t%s\n",
+				eld_connection_type_names[e->conn_type]);
+	snd_iprintf(buffer, "eld_version\t\t[0x%x] %s\n", e->eld_ver,
+					eld_version_names[e->eld_ver]);
+	snd_iprintf(buffer, "edid_version\t\t[0x%x] %s\n", e->cea_edid_ver,
+				cea_edid_version_names[e->cea_edid_ver]);
+	snd_iprintf(buffer, "manufacture_id\t\t0x%x\n", e->manufacture_id);
+	snd_iprintf(buffer, "product_id\t\t0x%x\n", e->product_id);
+	snd_iprintf(buffer, "port_id\t\t\t0x%llx\n", (long long)e->port_id);
+	snd_iprintf(buffer, "support_hdcp\t\t%d\n", e->support_hdcp);
+	snd_iprintf(buffer, "support_ai\t\t%d\n", e->support_ai);
+	snd_iprintf(buffer, "audio_sync_delay\t%d\n", e->aud_synch_delay);
+
+	snd_eld_print_channel_allocation(e->spk_alloc, buf, sizeof(buf));
+	snd_iprintf(buffer, "speakers\t\t[0x%x]%s\n", e->spk_alloc, buf);
+
+	snd_iprintf(buffer, "sad_count\t\t%d\n", e->sad_count);
+
+	for (i = 0; i < e->sad_count; i++)
+		hdmi_print_sad_info(i, e->sad + i, buffer);
+}
+EXPORT_SYMBOL_GPL(snd_print_eld_info);
+#endif /* CONFIG_SND_PROC_FS */
diff --git a/sound/core/pcm_misc.c b/sound/core/pcm_misc.c
index 4f556211bb56..d3a08e292072 100644
--- a/sound/core/pcm_misc.c
+++ b/sound/core/pcm_misc.c
@@ -432,9 +432,9 @@ int snd_pcm_format_set_silence(snd_pcm_format_t format, void *data, unsigned int
 	if (samples == 0)
 		return 0;
 	width = pcm_formats[(INT)format].phys; /* physical width */
-	pat = pcm_formats[(INT)format].silence;
-	if (!width || !pat)
+	if (!width)
 		return -EINVAL;
+	pat = pcm_formats[(INT)format].silence;
 	/* signed or 1 byte data */
 	if (pcm_formats[(INT)format].signd == 1 || width <= 8) {
 		unsigned int bytes = samples * width / 8;
diff --git a/sound/core/seq/oss/seq_oss_event.c b/sound/core/seq/oss/seq_oss_event.c
index 7b7c925dd3aa..76fb81077eef 100644
--- a/sound/core/seq/oss/seq_oss_event.c
+++ b/sound/core/seq/oss/seq_oss_event.c
@@ -290,16 +290,14 @@ note_on_event(struct seq_oss_devinfo *dp, int dev, int ch, int note, int vel, st
 		if (note == 255 && info->ch[ch].note >= 0) {
 			/* volume control */
 			int type;
-			//if (! vel)
-				/* set volume to zero -- note off */
-			//	type = SNDRV_SEQ_EVENT_NOTEOFF;
-			//else
-				if (info->ch[ch].vel)
+
+			if (info->ch[ch].vel)
 				/* sample already started -- volume change */
 				type = SNDRV_SEQ_EVENT_KEYPRESS;
 			else
 				/* sample not started -- start now */
 				type = SNDRV_SEQ_EVENT_NOTEON;
+
 			info->ch[ch].vel = vel;
 			return set_note_event(dp, dev, type, ch, info->ch[ch].note, vel, ev);
 		} else if (note >= 128)
diff --git a/sound/core/seq/seq_clientmgr.c b/sound/core/seq/seq_clientmgr.c
index 706f53e39b53..198c598a5393 100644
--- a/sound/core/seq/seq_clientmgr.c
+++ b/sound/core/seq/seq_clientmgr.c
@@ -1150,8 +1150,7 @@ static __poll_t snd_seq_poll(struct file *file, poll_table * wait)
 	if (snd_seq_file_flags(file) & SNDRV_SEQ_LFLG_OUTPUT) {
 
 		/* check if data is available in the pool */
-		if (!snd_seq_write_pool_allocated(client) ||
-		    snd_seq_pool_poll_wait(client->pool, file, wait))
+		if (snd_seq_pool_poll_wait(client->pool, file, wait))
 			mask |= EPOLLOUT | EPOLLWRNORM;
 	}
 
@@ -2586,8 +2585,6 @@ int snd_seq_kernel_client_write_poll(int clientid, struct file *file, poll_table
 	if (client == NULL)
 		return -ENXIO;
 
-	if (! snd_seq_write_pool_allocated(client))
-		return 1;
 	if (snd_seq_pool_poll_wait(client->pool, file, wait))
 		return 1;
 	return 0;
@@ -2729,6 +2726,7 @@ void snd_seq_info_clients_read(struct snd_info_entry *entry,
 			continue;
 		}
 
+		mutex_lock(&client->ioctl_mutex);
 		snd_iprintf(buffer, "Client %3d : \"%s\" [%s %s]\n",
 			    c, client->name,
 			    client->type == USER_CLIENT ? "User" : "Kernel",
@@ -2746,6 +2744,7 @@ void snd_seq_info_clients_read(struct snd_info_entry *entry,
 			snd_iprintf(buffer, "  Input pool :\n");
 			snd_seq_info_pool(buffer, client->data.user.fifo->pool, "    ");
 		}
+		mutex_unlock(&client->ioctl_mutex);
 		snd_seq_client_unlock(client);
 	}
 }
diff --git a/sound/core/seq/seq_memory.c b/sound/core/seq/seq_memory.c
index 20155e3e87c6..ccde0ca3d208 100644
--- a/sound/core/seq/seq_memory.c
+++ b/sound/core/seq/seq_memory.c
@@ -427,6 +427,7 @@ int snd_seq_pool_poll_wait(struct snd_seq_pool *pool, struct file *file,
 			   poll_table *wait)
 {
 	poll_wait(file, &pool->output_sleep, wait);
+	guard(spinlock_irq)(&pool->lock);
 	return snd_seq_output_ok(pool);
 }
 
diff --git a/sound/core/timer.c b/sound/core/timer.c
index fbada79380f9..1de4b90fd4d1 100644
--- a/sound/core/timer.c
+++ b/sound/core/timer.c
@@ -1152,7 +1152,7 @@ static int snd_timer_s_stop(struct snd_timer * timer)
 	unsigned long jiff;
 
 	priv = (struct snd_timer_system_private *) timer->private_data;
-	del_timer(&priv->tlist);
+	timer_delete(&priv->tlist);
 	jiff = jiffies;
 	if (time_before(jiff, priv->last_expires))
 		timer->sticks = priv->last_expires - jiff;
@@ -1167,7 +1167,7 @@ static int snd_timer_s_close(struct snd_timer *timer)
 	struct snd_timer_system_private *priv;
 
 	priv = (struct snd_timer_system_private *)timer->private_data;
-	del_timer_sync(&priv->tlist);
+	timer_delete_sync(&priv->tlist);
 	return 0;
 }
 
@@ -1515,91 +1515,97 @@ static void snd_timer_user_copy_id(struct snd_timer_id *id, struct snd_timer *ti
 	id->subdevice = timer->tmr_subdevice;
 }
 
-static int snd_timer_user_next_device(struct snd_timer_id __user *_tid)
+static void get_next_device(struct snd_timer_id *id)
 {
-	struct snd_timer_id id;
 	struct snd_timer *timer;
 	struct list_head *p;
 
-	if (copy_from_user(&id, _tid, sizeof(id)))
-		return -EFAULT;
-	guard(mutex)(&register_mutex);
-	if (id.dev_class < 0) {		/* first item */
+	if (id->dev_class < 0) {		/* first item */
 		if (list_empty(&snd_timer_list))
-			snd_timer_user_zero_id(&id);
+			snd_timer_user_zero_id(id);
 		else {
 			timer = list_entry(snd_timer_list.next,
 					   struct snd_timer, device_list);
-			snd_timer_user_copy_id(&id, timer);
+			snd_timer_user_copy_id(id, timer);
 		}
 	} else {
-		switch (id.dev_class) {
+		switch (id->dev_class) {
 		case SNDRV_TIMER_CLASS_GLOBAL:
-			id.device = id.device < 0 ? 0 : id.device + 1;
+			id->device = id->device < 0 ? 0 : id->device + 1;
 			list_for_each(p, &snd_timer_list) {
 				timer = list_entry(p, struct snd_timer, device_list);
 				if (timer->tmr_class > SNDRV_TIMER_CLASS_GLOBAL) {
-					snd_timer_user_copy_id(&id, timer);
+					snd_timer_user_copy_id(id, timer);
 					break;
 				}
-				if (timer->tmr_device >= id.device) {
-					snd_timer_user_copy_id(&id, timer);
+				if (timer->tmr_device >= id->device) {
+					snd_timer_user_copy_id(id, timer);
 					break;
 				}
 			}
 			if (p == &snd_timer_list)
-				snd_timer_user_zero_id(&id);
+				snd_timer_user_zero_id(id);
 			break;
 		case SNDRV_TIMER_CLASS_CARD:
 		case SNDRV_TIMER_CLASS_PCM:
-			if (id.card < 0) {
-				id.card = 0;
+			if (id->card < 0) {
+				id->card = 0;
 			} else {
-				if (id.device < 0) {
-					id.device = 0;
+				if (id->device < 0) {
+					id->device = 0;
 				} else {
-					if (id.subdevice < 0)
-						id.subdevice = 0;
-					else if (id.subdevice < INT_MAX)
-						id.subdevice++;
+					if (id->subdevice < 0)
+						id->subdevice = 0;
+					else if (id->subdevice < INT_MAX)
+						id->subdevice++;
 				}
 			}
 			list_for_each(p, &snd_timer_list) {
 				timer = list_entry(p, struct snd_timer, device_list);
-				if (timer->tmr_class > id.dev_class) {
-					snd_timer_user_copy_id(&id, timer);
+				if (timer->tmr_class > id->dev_class) {
+					snd_timer_user_copy_id(id, timer);
 					break;
 				}
-				if (timer->tmr_class < id.dev_class)
+				if (timer->tmr_class < id->dev_class)
 					continue;
-				if (timer->card->number > id.card) {
-					snd_timer_user_copy_id(&id, timer);
+				if (timer->card->number > id->card) {
+					snd_timer_user_copy_id(id, timer);
 					break;
 				}
-				if (timer->card->number < id.card)
+				if (timer->card->number < id->card)
 					continue;
-				if (timer->tmr_device > id.device) {
-					snd_timer_user_copy_id(&id, timer);
+				if (timer->tmr_device > id->device) {
+					snd_timer_user_copy_id(id, timer);
 					break;
 				}
-				if (timer->tmr_device < id.device)
+				if (timer->tmr_device < id->device)
 					continue;
-				if (timer->tmr_subdevice > id.subdevice) {
-					snd_timer_user_copy_id(&id, timer);
+				if (timer->tmr_subdevice > id->subdevice) {
+					snd_timer_user_copy_id(id, timer);
 					break;
 				}
-				if (timer->tmr_subdevice < id.subdevice)
+				if (timer->tmr_subdevice < id->subdevice)
 					continue;
-				snd_timer_user_copy_id(&id, timer);
+				snd_timer_user_copy_id(id, timer);
 				break;
 			}
 			if (p == &snd_timer_list)
-				snd_timer_user_zero_id(&id);
+				snd_timer_user_zero_id(id);
 			break;
 		default:
-			snd_timer_user_zero_id(&id);
+			snd_timer_user_zero_id(id);
 		}
 	}
+}
+
+static int snd_timer_user_next_device(struct snd_timer_id __user *_tid)
+{
+	struct snd_timer_id id;
+
+	if (copy_from_user(&id, _tid, sizeof(id)))
+		return -EFAULT;
+	scoped_guard(mutex, &register_mutex)
+		get_next_device(&id);
 	if (copy_to_user(_tid, &id, sizeof(*_tid)))
 		return -EFAULT;
 	return 0;
@@ -1620,23 +1626,24 @@ static int snd_timer_user_ginfo(struct file *file,
 	tid = ginfo->tid;
 	memset(ginfo, 0, sizeof(*ginfo));
 	ginfo->tid = tid;
-	guard(mutex)(&register_mutex);
-	t = snd_timer_find(&tid);
-	if (!t)
-		return -ENODEV;
-	ginfo->card = t->card ? t->card->number : -1;
-	if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
-		ginfo->flags |= SNDRV_TIMER_FLG_SLAVE;
-	strscpy(ginfo->id, t->id, sizeof(ginfo->id));
-	strscpy(ginfo->name, t->name, sizeof(ginfo->name));
-	scoped_guard(spinlock_irq, &t->lock)
-		ginfo->resolution = snd_timer_hw_resolution(t);
-	if (t->hw.resolution_min > 0) {
-		ginfo->resolution_min = t->hw.resolution_min;
-		ginfo->resolution_max = t->hw.resolution_max;
-	}
-	list_for_each(p, &t->open_list_head) {
-		ginfo->clients++;
+	scoped_guard(mutex, &register_mutex) {
+		t = snd_timer_find(&tid);
+		if (!t)
+			return -ENODEV;
+		ginfo->card = t->card ? t->card->number : -1;
+		if (t->hw.flags & SNDRV_TIMER_HW_SLAVE)
+			ginfo->flags |= SNDRV_TIMER_FLG_SLAVE;
+		strscpy(ginfo->id, t->id, sizeof(ginfo->id));
+		strscpy(ginfo->name, t->name, sizeof(ginfo->name));
+		scoped_guard(spinlock_irq, &t->lock)
+			ginfo->resolution = snd_timer_hw_resolution(t);
+		if (t->hw.resolution_min > 0) {
+			ginfo->resolution_min = t->hw.resolution_min;
+			ginfo->resolution_max = t->hw.resolution_max;
+		}
+		list_for_each(p, &t->open_list_head) {
+			ginfo->clients++;
+		}
 	}
 	if (copy_to_user(_ginfo, ginfo, sizeof(*ginfo)))
 		return -EFAULT;
@@ -1674,31 +1681,31 @@ static int snd_timer_user_gstatus(struct file *file,
 	struct snd_timer_gstatus gstatus;
 	struct snd_timer_id tid;
 	struct snd_timer *t;
-	int err = 0;
 
 	if (copy_from_user(&gstatus, _gstatus, sizeof(gstatus)))
 		return -EFAULT;
 	tid = gstatus.tid;
 	memset(&gstatus, 0, sizeof(gstatus));
 	gstatus.tid = tid;
-	guard(mutex)(&register_mutex);
-	t = snd_timer_find(&tid);
-	if (t != NULL) {
-		guard(spinlock_irq)(&t->lock);
-		gstatus.resolution = snd_timer_hw_resolution(t);
-		if (t->hw.precise_resolution) {
-			t->hw.precise_resolution(t, &gstatus.resolution_num,
-						 &gstatus.resolution_den);
+	scoped_guard(mutex, &register_mutex) {
+		t = snd_timer_find(&tid);
+		if (t != NULL) {
+			guard(spinlock_irq)(&t->lock);
+			gstatus.resolution = snd_timer_hw_resolution(t);
+			if (t->hw.precise_resolution) {
+				t->hw.precise_resolution(t, &gstatus.resolution_num,
+							 &gstatus.resolution_den);
+			} else {
+				gstatus.resolution_num = gstatus.resolution;
+				gstatus.resolution_den = 1000000000uL;
+			}
 		} else {
-			gstatus.resolution_num = gstatus.resolution;
-			gstatus.resolution_den = 1000000000uL;
+			return -ENODEV;
 		}
-	} else {
-		err = -ENODEV;
 	}
-	if (err >= 0 && copy_to_user(_gstatus, &gstatus, sizeof(gstatus)))
-		err = -EFAULT;
-	return err;
+	if (copy_to_user(_gstatus, &gstatus, sizeof(gstatus)))
+		return -EFAULT;
+	return 0;
 }
 
 static int snd_timer_user_tselect(struct file *file,