--- zzzz-none-000/linux-3.10.107/sound/usb/mixer_maps.c	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/sound/usb/mixer_maps.c	2021-02-04 17:41:59.000000000 +0000
@@ -179,6 +179,11 @@
 	{ 0 } /* terminator */
 };
 
+static struct usbmix_name_map mbox1_map[] = {
+	{ 1, "Clock" },
+	{ 0 } /* terminator */
+};
+
 static struct usbmix_selector_map c400_selectors[] = {
 	{
 		.id = 0x80,
@@ -322,6 +327,12 @@
 	{ 0 }				/* terminator */
 };
 
+/* Plantronics Gamecom 780 has a broken volume control, better to disable it */
+static struct usbmix_name_map gamecom780_map[] = {
+	{ 9, NULL }, /* FU, speaker out */
+	{}
+};
+
 /* some (all?) SCMS USB3318 devices are affected by a firmware lock up
  * when anything attempts to access FU 10 (control)
  */
@@ -337,11 +348,14 @@
 	{ 0 }	/* terminator */
 };
 
-/* Dragonfly DAC 1.2, the dB conversion factor is 1 instead of 256 */
-static struct usbmix_dB_map dragonfly_1_2_dB = {0, 5000};
-static struct usbmix_name_map dragonfly_1_2_map[] = {
-	{ 7, NULL, .dB = &dragonfly_1_2_dB },
-	{ 0 }	/* terminator */
+/*
+ * Dell usb dock with ALC4020 codec had a firmware problem where it got
+ * screwed up when zero volume is passed; just skip it as a workaround
+ */
+static const struct usbmix_name_map dell_alc4020_map[] = {
+	{ 16, NULL },
+	{ 19, NULL },
+	{ 0 }
 };
 
 /*
@@ -380,6 +394,10 @@
 		.id = USB_ID(0x046d, 0x09a4),
 		.ignore_ctl_error = 1,
 	},
+	{	/* Plantronics GameCom 780 */
+		.id = USB_ID(0x047f, 0xc010),
+		.map = gamecom780_map,
+	},
 	{
 		/* Hercules DJ Console (Windows Edition) */
 		.id = USB_ID(0x06f8, 0xb000),
@@ -423,6 +441,14 @@
 		.map = aureon_51_2_map,
 	},
 	{
+		.id = USB_ID(0x0bda, 0x4014),
+		.map = dell_alc4020_map,
+	},
+	{
+		.id = USB_ID(0x0dba, 0x1000),
+		.map = mbox1_map,
+	},
+	{
 		.id = USB_ID(0x13e5, 0x0001),
 		.map = scratch_live_map,
 		.ignore_ctl_error = 1,
@@ -451,11 +477,6 @@
 		.id = USB_ID(0x05a7, 0x1020),
 		.map = bose_companion5_map,
 	},
-	{
-		/* Dragonfly DAC 1.2 */
-		.id = USB_ID(0x21b4, 0x0081),
-		.map = dragonfly_1_2_map,
-	},
 	{ 0 } /* terminator */
 };