diff --git a/include/sound/emu10k1.h b/include/sound/emu10k1.h
index 43c097952c3c..7c55a8244747 100644
--- a/include/sound/emu10k1.h
+++ b/include/sound/emu10k1.h
@@ -992,6 +992,9 @@ SUB_REG_NC(A_EHC, A_I2S_CAPTURE_RATE, 0x00000e00)  /* This sets the capture PCM
 #define EMU_HANA_WCLOCK_4X		0x10
 #define EMU_HANA_WCLOCK_MULT_RESERVED	0x18
 
+// If the selected external clock source is/becomes invalid or incompatible
+// with the clock multiplier, the clock source is reset to this value, and
+// a WCLK_CHANGED interrupt is raised.
 #define EMU_HANA_DEFCLOCK	0x06	/* 000000x  1 bits Default Word Clock  */
 #define EMU_HANA_DEFCLOCK_48K		0x00
 #define EMU_HANA_DEFCLOCK_44_1K		0x01
@@ -1679,6 +1682,7 @@ struct snd_emu1010 {
 	unsigned int optical_in; /* 0:SPDIF, 1:ADAT */
 	unsigned int optical_out; /* 0:SPDIF, 1:ADAT */
 	struct work_struct firmware_work;
+	struct work_struct clock_work;
 };
 
 struct snd_emu10k1 {
@@ -1753,6 +1757,7 @@ struct snd_emu10k1 {
 	struct snd_kcontrol *ctl_efx_send_routing;
 	struct snd_kcontrol *ctl_efx_send_volume;
 	struct snd_kcontrol *ctl_efx_attn;
+	struct snd_kcontrol *ctl_clock_source;
 
 	void (*hwvol_interrupt)(struct snd_emu10k1 *emu, unsigned int status);
 	void (*capture_interrupt)(struct snd_emu10k1 *emu, unsigned int status);
diff --git a/sound/pci/emu10k1/emu10k1.c b/sound/pci/emu10k1/emu10k1.c
index 1a13c086e86c..421053569aa0 100644
--- a/sound/pci/emu10k1/emu10k1.c
+++ b/sound/pci/emu10k1/emu10k1.c
@@ -192,6 +192,7 @@ static int snd_emu10k1_suspend(struct device *dev)
 	emu->suspend = 1;
 
 	cancel_work_sync(&emu->emu1010.firmware_work);
+	cancel_work_sync(&emu->emu1010.clock_work);
 
 	snd_ac97_suspend(emu->ac97);
 
diff --git a/sound/pci/emu10k1/emu10k1_main.c b/sound/pci/emu10k1/emu10k1_main.c
index a11fcba4b9af..604645bfc908 100644
--- a/sound/pci/emu10k1/emu10k1_main.c
+++ b/sound/pci/emu10k1/emu10k1_main.c
@@ -789,6 +789,30 @@ static void emu1010_firmware_work(struct work_struct *work)
 	}
 }
 
+static void emu1010_clock_work(struct work_struct *work)
+{
+	struct snd_emu10k1 *emu;
+	struct snd_ctl_elem_id id;
+
+	emu = container_of(work, struct snd_emu10k1,
+			   emu1010.clock_work);
+	if (emu->card->shutdown)
+		return;
+#ifdef CONFIG_PM_SLEEP
+	if (emu->suspend)
+		return;
+#endif
+
+	spin_lock_irq(&emu->reg_lock);
+	// This is the only thing that can actually happen.
+	emu->emu1010.clock_source = emu->emu1010.clock_fallback;
+	emu->emu1010.wclock = 1 - emu->emu1010.clock_source;
+	snd_emu1010_update_clock(emu);
+	spin_unlock_irq(&emu->reg_lock);
+	snd_ctl_build_ioff(&id, emu->ctl_clock_source, 0);
+	snd_ctl_notify(emu->card, SNDRV_CTL_EVENT_MASK_VALUE, &id);
+}
+
 static void emu1010_interrupt(struct snd_emu10k1 *emu)
 {
 	u32 sts;
@@ -802,6 +826,8 @@ static void emu1010_interrupt(struct snd_emu10k1 *emu)
 	} else if (sts & EMU_HANA_IRQ_DOCK) {
 		schedule_work(&emu->emu1010.firmware_work);
 	}
+	if (sts & EMU_HANA_IRQ_WCLK_CHANGED)
+		schedule_work(&emu->emu1010.clock_work);
 }
 
 /*
@@ -901,7 +927,7 @@ static int snd_emu10k1_emu1010_init(struct snd_emu10k1 *emu)
 	emu->gpio_interrupt = emu1010_interrupt;
 	// Note: The Audigy INTE is set later
 	snd_emu1010_fpga_write(emu, EMU_HANA_IRQ_ENABLE,
-			       EMU_HANA_IRQ_DOCK | EMU_HANA_IRQ_DOCK_LOST);
+			       EMU_HANA_IRQ_DOCK | EMU_HANA_IRQ_DOCK_LOST | EMU_HANA_IRQ_WCLK_CHANGED);
 	snd_emu1010_fpga_read(emu, EMU_HANA_IRQ_STATUS, &reg);  // Clear pending IRQs
 
 	emu->emu1010.clock_source = 1;  /* 48000 */
@@ -943,6 +969,7 @@ static void snd_emu10k1_free(struct snd_card *card)
 		snd_emu1010_fpga_write(emu, EMU_HANA_DOCK_PWR, 0);
 	}
 	cancel_work_sync(&emu->emu1010.firmware_work);
+	cancel_work_sync(&emu->emu1010.clock_work);
 	release_firmware(emu->firmware);
 	release_firmware(emu->dock_fw);
 	snd_util_memhdr_free(emu->memhdr);
@@ -1522,6 +1549,7 @@ int snd_emu10k1_create(struct snd_card *card,
 	emu->synth = NULL;
 	emu->get_synth_voice = NULL;
 	INIT_WORK(&emu->emu1010.firmware_work, emu1010_firmware_work);
+	INIT_WORK(&emu->emu1010.clock_work, emu1010_clock_work);
 	/* read revision & serial */
 	emu->revision = pci->revision;
 	pci_read_config_dword(pci, PCI_SUBSYSTEM_VENDOR_ID, &emu->serial);
diff --git a/sound/pci/emu10k1/emumixer.c b/sound/pci/emu10k1/emumixer.c
index 9a94f08f2463..f39025748072 100644
--- a/sound/pci/emu10k1/emumixer.c
+++ b/sound/pci/emu10k1/emumixer.c
@@ -986,17 +986,21 @@ static int snd_emu1010_clock_source_put(struct snd_kcontrol *kcontrol,
 	val = ucontrol->value.enumerated.item[0] ;
 	if (val >= emu_ci->num)
 		return -EINVAL;
+	spin_lock_irq(&emu->reg_lock);
 	change = (emu->emu1010.clock_source != val);
 	if (change) {
 		emu->emu1010.clock_source = val;
 		emu->emu1010.wclock = emu_ci->vals[val];
+		snd_emu1010_update_clock(emu);
 
 		snd_emu1010_fpga_write(emu, EMU_HANA_UNMUTE, EMU_MUTE);
 		snd_emu1010_fpga_write(emu, EMU_HANA_WCLOCK, emu->emu1010.wclock);
+		spin_unlock_irq(&emu->reg_lock);
+
 		msleep(10);  // Allow DLL to settle
 		snd_emu1010_fpga_write(emu, EMU_HANA_UNMUTE, EMU_UNMUTE);
-
-		snd_emu1010_update_clock(emu);
+	} else {
+		spin_unlock_irq(&emu->reg_lock);
 	}
 	return change;
 }
@@ -2336,8 +2340,8 @@ int snd_emu10k1_mixer(struct snd_emu10k1 *emu,
 				emu1010_map_source(emu_ri, emu_ri->out_dflts[i]);
 		snd_emu1010_apply_sources(emu);
 
-		err = snd_ctl_add(card,
-			snd_ctl_new1(&snd_emu1010_clock_source, emu));
+		kctl = emu->ctl_clock_source = snd_ctl_new1(&snd_emu1010_clock_source, emu);
+		err = snd_ctl_add(card, kctl);
 		if (err < 0)
 			return err;
 		err = snd_ctl_add(card,