Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 619 insertions, 0 deletions

diff --git a/sound/usb/6fire/control.c b/sound/usb/6fire/control.c
new file mode 100644
index 000000000..10104cb42
--- /dev/null
+++ b/sound/usb/6fire/control.c
@@ -0,0 +1,619 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Linux driver for TerraTec DMX 6Fire USB
+ *
+ * Mixer control
+ *
+ * Author:	Torsten Schenk <torsten.schenk@zoho.com>
+ * Created:	Jan 01, 2011
+ * Copyright:	(C) Torsten Schenk
+ *
+ * Thanks to:
+ * - Holger Ruckdeschel: he found out how to control individual channel
+ *   volumes and introduced mute switch
+ */
+
+#include <linux/interrupt.h>
+#include <sound/control.h>
+#include <sound/tlv.h>
+
+#include "control.h"
+#include "comm.h"
+#include "chip.h"
+
+static const char * const opt_coax_texts[2] = { "Optical", "Coax" };
+static const char * const line_phono_texts[2] = { "Line", "Phono" };
+
+/*
+ * data that needs to be sent to device. sets up card internal stuff.
+ * values dumped from windows driver and filtered by trial'n'error.
+ */
+static const struct {
+	u8 type;
+	u8 reg;
+	u8 value;
+}
+init_data[] = {
+	{ 0x22, 0x00, 0x00 }, { 0x20, 0x00, 0x08 }, { 0x22, 0x01, 0x01 },
+	{ 0x20, 0x01, 0x08 }, { 0x22, 0x02, 0x00 }, { 0x20, 0x02, 0x08 },
+	{ 0x22, 0x03, 0x00 }, { 0x20, 0x03, 0x08 }, { 0x22, 0x04, 0x00 },
+	{ 0x20, 0x04, 0x08 }, { 0x22, 0x05, 0x01 }, { 0x20, 0x05, 0x08 },
+	{ 0x22, 0x04, 0x01 }, { 0x12, 0x04, 0x00 }, { 0x12, 0x05, 0x00 },
+	{ 0x12, 0x0d, 0x38 }, { 0x12, 0x21, 0x82 }, { 0x12, 0x22, 0x80 },
+	{ 0x12, 0x23, 0x00 }, { 0x12, 0x06, 0x02 }, { 0x12, 0x03, 0x00 },
+	{ 0x12, 0x02, 0x00 }, { 0x22, 0x03, 0x01 },
+	{ 0 } /* TERMINATING ENTRY */
+};
+
+static const int rates_altsetting[] = { 1, 1, 2, 2, 3, 3 };
+/* values to write to soundcard register for all samplerates */
+static const u16 rates_6fire_vl[] = {0x00, 0x01, 0x00, 0x01, 0x00, 0x01};
+static const u16 rates_6fire_vh[] = {0x11, 0x11, 0x10, 0x10, 0x00, 0x00};
+
+static DECLARE_TLV_DB_MINMAX(tlv_output, -9000, 0);
+static DECLARE_TLV_DB_MINMAX(tlv_input, -1500, 1500);
+
+enum {
+	DIGITAL_THRU_ONLY_SAMPLERATE = 3
+};
+
+static void usb6fire_control_output_vol_update(struct control_runtime *rt)
+{
+	struct comm_runtime *comm_rt = rt->chip->comm;
+	int i;
+
+	if (comm_rt)
+		for (i = 0; i < 6; i++)
+			if (!(rt->ovol_updated & (1 << i))) {
+				comm_rt->write8(comm_rt, 0x12, 0x0f + i,
+					180 - rt->output_vol[i]);
+				rt->ovol_updated |= 1 << i;
+			}
+}
+
+static void usb6fire_control_output_mute_update(struct control_runtime *rt)
+{
+	struct comm_runtime *comm_rt = rt->chip->comm;
+
+	if (comm_rt)
+		comm_rt->write8(comm_rt, 0x12, 0x0e, ~rt->output_mute);
+}
+
+static void usb6fire_control_input_vol_update(struct control_runtime *rt)
+{
+	struct comm_runtime *comm_rt = rt->chip->comm;
+	int i;
+
+	if (comm_rt)
+		for (i = 0; i < 2; i++)
+			if (!(rt->ivol_updated & (1 << i))) {
+				comm_rt->write8(comm_rt, 0x12, 0x1c + i,
+					rt->input_vol[i] & 0x3f);
+				rt->ivol_updated |= 1 << i;
+			}
+}
+
+static void usb6fire_control_line_phono_update(struct control_runtime *rt)
+{
+	struct comm_runtime *comm_rt = rt->chip->comm;
+	if (comm_rt) {
+		comm_rt->write8(comm_rt, 0x22, 0x02, rt->line_phono_switch);
+		comm_rt->write8(comm_rt, 0x21, 0x02, rt->line_phono_switch);
+	}
+}
+
+static void usb6fire_control_opt_coax_update(struct control_runtime *rt)
+{
+	struct comm_runtime *comm_rt = rt->chip->comm;
+	if (comm_rt) {
+		comm_rt->write8(comm_rt, 0x22, 0x00, rt->opt_coax_switch);
+		comm_rt->write8(comm_rt, 0x21, 0x00, rt->opt_coax_switch);
+	}
+}
+
+static int usb6fire_control_set_rate(struct control_runtime *rt, int rate)
+{
+	int ret;
+	struct usb_device *device = rt->chip->dev;
+	struct comm_runtime *comm_rt = rt->chip->comm;
+
+	if (rate < 0 || rate >= CONTROL_N_RATES)
+		return -EINVAL;
+
+	ret = usb_set_interface(device, 1, rates_altsetting[rate]);
+	if (ret < 0)
+		return ret;
+
+	/* set soundcard clock */
+	ret = comm_rt->write16(comm_rt, 0x02, 0x01, rates_6fire_vl[rate],
+			rates_6fire_vh[rate]);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+static int usb6fire_control_set_channels(
+	struct control_runtime *rt, int n_analog_out,
+	int n_analog_in, bool spdif_out, bool spdif_in)
+{
+	int ret;
+	struct comm_runtime *comm_rt = rt->chip->comm;
+
+	/* enable analog inputs and outputs
+	 * (one bit per stereo-channel) */
+	ret = comm_rt->write16(comm_rt, 0x02, 0x02,
+			(1 << (n_analog_out / 2)) - 1,
+			(1 << (n_analog_in / 2)) - 1);
+	if (ret < 0)
+		return ret;
+
+	/* disable digital inputs and outputs */
+	/* TODO: use spdif_x to enable/disable digital channels */
+	ret = comm_rt->write16(comm_rt, 0x02, 0x03, 0x00, 0x00);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+static int usb6fire_control_streaming_update(struct control_runtime *rt)
+{
+	struct comm_runtime *comm_rt = rt->chip->comm;
+
+	if (comm_rt) {
+		if (!rt->usb_streaming && rt->digital_thru_switch)
+			usb6fire_control_set_rate(rt,
+				DIGITAL_THRU_ONLY_SAMPLERATE);
+		return comm_rt->write16(comm_rt, 0x02, 0x00, 0x00,
+			(rt->usb_streaming ? 0x01 : 0x00) |
+			(rt->digital_thru_switch ? 0x08 : 0x00));
+	}
+	return -EINVAL;
+}
+
+static int usb6fire_control_output_vol_info(struct snd_kcontrol *kcontrol,
+		struct snd_ctl_elem_info *uinfo)
+{
+	uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
+	uinfo->count = 2;
+	uinfo->value.integer.min = 0;
+	uinfo->value.integer.max = 180;
+	return 0;
+}
+
+static int usb6fire_control_output_vol_put(struct snd_kcontrol *kcontrol,
+		struct snd_ctl_elem_value *ucontrol)
+{
+	struct control_runtime *rt = snd_kcontrol_chip(kcontrol);
+	unsigned int ch = kcontrol->private_value;
+	int changed = 0;
+
+	if (ch > 4) {
+		dev_err(&rt->chip->dev->dev,
+			"Invalid channel in volume control.");
+		return -EINVAL;
+	}
+
+	if (rt->output_vol[ch] != ucontrol->value.integer.value[0]) {
+		rt->output_vol[ch] = ucontrol->value.integer.value[0];
+		rt->ovol_updated &= ~(1 << ch);
+		changed = 1;
+	}
+	if (rt->output_vol[ch + 1] != ucontrol->value.integer.value[1]) {
+		rt->output_vol[ch + 1] = ucontrol->value.integer.value[1];
+		rt->ovol_updated &= ~(2 << ch);
+		changed = 1;
+	}
+
+	if (changed)
+		usb6fire_control_output_vol_update(rt);
+
+	return changed;
+}
+
+static int usb6fire_control_output_vol_get(struct snd_kcontrol *kcontrol,
+		struct snd_ctl_elem_value *ucontrol)
+{
+	struct control_runtime *rt = snd_kcontrol_chip(kcontrol);
+	unsigned int ch = kcontrol->private_value;
+
+	if (ch > 4) {
+		dev_err(&rt->chip->dev->dev,
+			"Invalid channel in volume control.");
+		return -EINVAL;
+	}
+
+	ucontrol->value.integer.value[0] = rt->output_vol[ch];
+	ucontrol->value.integer.value[1] = rt->output_vol[ch + 1];
+	return 0;
+}
+
+static int usb6fire_control_output_mute_put(struct snd_kcontrol *kcontrol,
+	struct snd_ctl_elem_value *ucontrol)
+{
+	struct control_runtime *rt = snd_kcontrol_chip(kcontrol);
+	unsigned int ch = kcontrol->private_value;
+	u8 old = rt->output_mute;
+	u8 value = 0;
+
+	if (ch > 4) {
+		dev_err(&rt->chip->dev->dev,
+			"Invalid channel in volume control.");
+		return -EINVAL;
+	}
+
+	rt->output_mute &= ~(3 << ch);
+	if (ucontrol->value.integer.value[0])
+		value |= 1;
+	if (ucontrol->value.integer.value[1])
+		value |= 2;
+	rt->output_mute |= value << ch;
+
+	if (rt->output_mute != old)
+		usb6fire_control_output_mute_update(rt);
+
+	return rt->output_mute != old;
+}
+
+static int usb6fire_control_output_mute_get(struct snd_kcontrol *kcontrol,
+	struct snd_ctl_elem_value *ucontrol)
+{
+	struct control_runtime *rt = snd_kcontrol_chip(kcontrol);
+	unsigned int ch = kcontrol->private_value;
+	u8 value = rt->output_mute >> ch;
+
+	if (ch > 4) {
+		dev_err(&rt->chip->dev->dev,
+			"Invalid channel in volume control.");
+		return -EINVAL;
+	}
+
+	ucontrol->value.integer.value[0] = 1 & value;
+	value >>= 1;
+	ucontrol->value.integer.value[1] = 1 & value;
+
+	return 0;
+}
+
+static int usb6fire_control_input_vol_info(struct snd_kcontrol *kcontrol,
+		struct snd_ctl_elem_info *uinfo)
+{
+	uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
+	uinfo->count = 2;
+	uinfo->value.integer.min = 0;
+	uinfo->value.integer.max = 30;
+	return 0;
+}
+
+static int usb6fire_control_input_vol_put(struct snd_kcontrol *kcontrol,
+		struct snd_ctl_elem_value *ucontrol)
+{
+	struct control_runtime *rt = snd_kcontrol_chip(kcontrol);
+	int vol0 = ucontrol->value.integer.value[0] - 15;
+	int vol1 = ucontrol->value.integer.value[1] - 15;
+	int changed = 0;
+
+	if (rt->input_vol[0] != vol0) {
+		rt->input_vol[0] = vol0;
+		rt->ivol_updated &= ~(1 << 0);
+		changed = 1;
+	}
+	if (rt->input_vol[1] != vol1) {
+		rt->input_vol[1] = vol1;
+		rt->ivol_updated &= ~(1 << 1);
+		changed = 1;
+	}
+
+	if (changed)
+		usb6fire_control_input_vol_update(rt);
+
+	return changed;
+}
+
+static int usb6fire_control_input_vol_get(struct snd_kcontrol *kcontrol,
+		struct snd_ctl_elem_value *ucontrol)
+{
+	struct control_runtime *rt = snd_kcontrol_chip(kcontrol);
+
+	ucontrol->value.integer.value[0] = rt->input_vol[0] + 15;
+	ucontrol->value.integer.value[1] = rt->input_vol[1] + 15;
+
+	return 0;
+}
+
+static int usb6fire_control_line_phono_info(struct snd_kcontrol *kcontrol,
+		struct snd_ctl_elem_info *uinfo)
+{
+	return snd_ctl_enum_info(uinfo, 1, 2, line_phono_texts);
+}
+
+static int usb6fire_control_line_phono_put(struct snd_kcontrol *kcontrol,
+		struct snd_ctl_elem_value *ucontrol)
+{
+	struct control_runtime *rt = snd_kcontrol_chip(kcontrol);
+	int changed = 0;
+	if (rt->line_phono_switch != ucontrol->value.integer.value[0]) {
+		rt->line_phono_switch = ucontrol->value.integer.value[0];
+		usb6fire_control_line_phono_update(rt);
+		changed = 1;
+	}
+	return changed;
+}
+
+static int usb6fire_control_line_phono_get(struct snd_kcontrol *kcontrol,
+		struct snd_ctl_elem_value *ucontrol)
+{
+	struct control_runtime *rt = snd_kcontrol_chip(kcontrol);
+	ucontrol->value.integer.value[0] = rt->line_phono_switch;
+	return 0;
+}
+
+static int usb6fire_control_opt_coax_info(struct snd_kcontrol *kcontrol,
+		struct snd_ctl_elem_info *uinfo)
+{
+	return snd_ctl_enum_info(uinfo, 1, 2, opt_coax_texts);
+}
+
+static int usb6fire_control_opt_coax_put(struct snd_kcontrol *kcontrol,
+		struct snd_ctl_elem_value *ucontrol)
+{
+	struct control_runtime *rt = snd_kcontrol_chip(kcontrol);
+	int changed = 0;
+
+	if (rt->opt_coax_switch != ucontrol->value.enumerated.item[0]) {
+		rt->opt_coax_switch = ucontrol->value.enumerated.item[0];
+		usb6fire_control_opt_coax_update(rt);
+		changed = 1;
+	}
+	return changed;
+}
+
+static int usb6fire_control_opt_coax_get(struct snd_kcontrol *kcontrol,
+		struct snd_ctl_elem_value *ucontrol)
+{
+	struct control_runtime *rt = snd_kcontrol_chip(kcontrol);
+	ucontrol->value.enumerated.item[0] = rt->opt_coax_switch;
+	return 0;
+}
+
+static int usb6fire_control_digital_thru_put(struct snd_kcontrol *kcontrol,
+		struct snd_ctl_elem_value *ucontrol)
+{
+	struct control_runtime *rt = snd_kcontrol_chip(kcontrol);
+	int changed = 0;
+
+	if (rt->digital_thru_switch != ucontrol->value.integer.value[0]) {
+		rt->digital_thru_switch = ucontrol->value.integer.value[0];
+		usb6fire_control_streaming_update(rt);
+		changed = 1;
+	}
+	return changed;
+}
+
+static int usb6fire_control_digital_thru_get(struct snd_kcontrol *kcontrol,
+		struct snd_ctl_elem_value *ucontrol)
+{
+	struct control_runtime *rt = snd_kcontrol_chip(kcontrol);
+	ucontrol->value.integer.value[0] = rt->digital_thru_switch;
+	return 0;
+}
+
+static const struct snd_kcontrol_new vol_elements[] = {
+	{
+		.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
+		.name = "Analog Playback Volume",
+		.index = 0,
+		.private_value = 0,
+		.access = SNDRV_CTL_ELEM_ACCESS_READWRITE |
+			SNDRV_CTL_ELEM_ACCESS_TLV_READ,
+		.info = usb6fire_control_output_vol_info,
+		.get = usb6fire_control_output_vol_get,
+		.put = usb6fire_control_output_vol_put,
+		.tlv = { .p = tlv_output }
+	},
+	{
+		.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
+		.name = "Analog Playback Volume",
+		.index = 1,
+		.private_value = 2,
+		.access = SNDRV_CTL_ELEM_ACCESS_READWRITE |
+			SNDRV_CTL_ELEM_ACCESS_TLV_READ,
+		.info = usb6fire_control_output_vol_info,
+		.get = usb6fire_control_output_vol_get,
+		.put = usb6fire_control_output_vol_put,
+		.tlv = { .p = tlv_output }
+	},
+	{
+		.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
+		.name = "Analog Playback Volume",
+		.index = 2,
+		.private_value = 4,
+		.access = SNDRV_CTL_ELEM_ACCESS_READWRITE |
+			SNDRV_CTL_ELEM_ACCESS_TLV_READ,
+		.info = usb6fire_control_output_vol_info,
+		.get = usb6fire_control_output_vol_get,
+		.put = usb6fire_control_output_vol_put,
+		.tlv = { .p = tlv_output }
+	},
+	{}
+};
+
+static const struct snd_kcontrol_new mute_elements[] = {
+	{
+		.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
+		.name = "Analog Playback Switch",
+		.index = 0,
+		.private_value = 0,
+		.access = SNDRV_CTL_ELEM_ACCESS_READWRITE,
+		.info = snd_ctl_boolean_stereo_info,
+		.get = usb6fire_control_output_mute_get,
+		.put = usb6fire_control_output_mute_put,
+	},
+	{
+		.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
+		.name = "Analog Playback Switch",
+		.index = 1,
+		.private_value = 2,
+		.access = SNDRV_CTL_ELEM_ACCESS_READWRITE,
+		.info = snd_ctl_boolean_stereo_info,
+		.get = usb6fire_control_output_mute_get,
+		.put = usb6fire_control_output_mute_put,
+	},
+	{
+		.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
+		.name = "Analog Playback Switch",
+		.index = 2,
+		.private_value = 4,
+		.access = SNDRV_CTL_ELEM_ACCESS_READWRITE,
+		.info = snd_ctl_boolean_stereo_info,
+		.get = usb6fire_control_output_mute_get,
+		.put = usb6fire_control_output_mute_put,
+	},
+	{}
+};
+
+static const struct snd_kcontrol_new elements[] = {
+	{
+		.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
+		.name = "Line/Phono Capture Route",
+		.index = 0,
+		.access = SNDRV_CTL_ELEM_ACCESS_READWRITE,
+		.info = usb6fire_control_line_phono_info,
+		.get = usb6fire_control_line_phono_get,
+		.put = usb6fire_control_line_phono_put
+	},
+	{
+		.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
+		.name = "Opt/Coax Capture Route",
+		.index = 0,
+		.access = SNDRV_CTL_ELEM_ACCESS_READWRITE,
+		.info = usb6fire_control_opt_coax_info,
+		.get = usb6fire_control_opt_coax_get,
+		.put = usb6fire_control_opt_coax_put
+	},
+	{
+		.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
+		.name = "Digital Thru Playback Route",
+		.index = 0,
+		.access = SNDRV_CTL_ELEM_ACCESS_READWRITE,
+		.info = snd_ctl_boolean_mono_info,
+		.get = usb6fire_control_digital_thru_get,
+		.put = usb6fire_control_digital_thru_put
+	},
+	{
+		.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
+		.name = "Analog Capture Volume",
+		.index = 0,
+		.access = SNDRV_CTL_ELEM_ACCESS_READWRITE |
+			SNDRV_CTL_ELEM_ACCESS_TLV_READ,
+		.info = usb6fire_control_input_vol_info,
+		.get = usb6fire_control_input_vol_get,
+		.put = usb6fire_control_input_vol_put,
+		.tlv = { .p = tlv_input }
+	},
+	{}
+};
+
+static int usb6fire_control_add_virtual(
+	struct control_runtime *rt,
+	struct snd_card *card,
+	char *name,
+	const struct snd_kcontrol_new *elems)
+{
+	int ret;
+	int i;
+	struct snd_kcontrol *vmaster =
+		snd_ctl_make_virtual_master(name, tlv_output);
+	struct snd_kcontrol *control;
+
+	if (!vmaster)
+		return -ENOMEM;
+	ret = snd_ctl_add(card, vmaster);
+	if (ret < 0)
+		return ret;
+
+	i = 0;
+	while (elems[i].name) {
+		control = snd_ctl_new1(&elems[i], rt);
+		if (!control)
+			return -ENOMEM;
+		ret = snd_ctl_add(card, control);
+		if (ret < 0)
+			return ret;
+		ret = snd_ctl_add_follower(vmaster, control);
+		if (ret < 0)
+			return ret;
+		i++;
+	}
+	return 0;
+}
+
+int usb6fire_control_init(struct sfire_chip *chip)
+{
+	int i;
+	int ret;
+	struct control_runtime *rt = kzalloc_obj(struct control_runtime);
+	struct comm_runtime *comm_rt = chip->comm;
+
+	if (!rt)
+		return -ENOMEM;
+
+	rt->chip = chip;
+	rt->update_streaming = usb6fire_control_streaming_update;
+	rt->set_rate = usb6fire_control_set_rate;
+	rt->set_channels = usb6fire_control_set_channels;
+
+	i = 0;
+	while (init_data[i].type) {
+		comm_rt->write8(comm_rt, init_data[i].type, init_data[i].reg,
+				init_data[i].value);
+		i++;
+	}
+
+	usb6fire_control_opt_coax_update(rt);
+	usb6fire_control_line_phono_update(rt);
+	usb6fire_control_output_vol_update(rt);
+	usb6fire_control_output_mute_update(rt);
+	usb6fire_control_input_vol_update(rt);
+	usb6fire_control_streaming_update(rt);
+
+	ret = usb6fire_control_add_virtual(rt, chip->card,
+		"Master Playback Volume", vol_elements);
+	if (ret) {
+		dev_err(&chip->dev->dev, "cannot add control.\n");
+		goto free_rt;
+	}
+	ret = usb6fire_control_add_virtual(rt, chip->card,
+		"Master Playback Switch", mute_elements);
+	if (ret) {
+		dev_err(&chip->dev->dev, "cannot add control.\n");
+		goto free_rt;
+	}
+
+	i = 0;
+	while (elements[i].name) {
+		ret = snd_ctl_add(chip->card, snd_ctl_new1(&elements[i], rt));
+		if (ret < 0) {
+			dev_err(&chip->dev->dev, "cannot add control.\n");
+			goto free_rt;
+		}
+		i++;
+	}
+
+	chip->control = rt;
+	return 0;
+
+free_rt:
+	kfree(rt);
+	return ret;
+}
+
+void usb6fire_control_abort(struct sfire_chip *chip)
+{}
+
+void usb6fire_control_destroy(struct sfire_chip *chip)
+{
+	kfree(chip->control);
+	chip->control = NULL;
+}