2 files changed, 24 insertions, 0 deletions

diff --git a/sound/usb/mixer_maps.c b/sound/usb/mixer_maps.c
index cc2dd1f0decb..32af6b741ef5 100644
--- a/sound/usb/mixer_maps.c
+++ b/sound/usb/mixer_maps.c
@@ -322,6 +322,12 @@ static struct usbmix_name_map hercules_usb51_map[] = {
         { 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 */
+        {}
+};
+
 /*
  * Control map entries
  */
@@ -358,6 +364,10 @@ static struct usbmix_ctl_map usbmix_ctl_maps[] = {
                 .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),
diff --git a/sound/usb/quirks.c b/sound/usb/quirks.c
index 0df9ede99dfd..ede753685491 100644
--- a/sound/usb/quirks.c
+++ b/sound/usb/quirks.c
@@ -660,6 +660,18 @@ static int snd_usb_cm6206_boot_quirk(struct usb_device *dev)
         return err;
 }
 
+/* quirk for Plantronics GameCom 780 with CM6302 chip */
+static int snd_usb_gamecon780_boot_quirk(struct usb_device *dev)
+{
+        /* set the initial volume and don't change; other values are either
+         * too loud or silent due to firmware bug (bko#65251)
+         */
+        u8 buf[2] = { 0x74, 0xdc };
+        return snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC_SET_CUR,
+                        USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_OUT,
+                        UAC_FU_VOLUME << 8, 9 << 8, buf, 2);
+}
+
 /*
  * Novation Twitch DJ controller
  */
@@ -986,6 +998,8 @@ int snd_usb_apply_boot_quirk(struct usb_device *dev,
                 return snd_usb_nativeinstruments_boot_quirk(dev);
         case USB_ID(0x0763, 0x2012):  /* M-Audio Fast Track Pro USB */
                 return snd_usb_fasttrackpro_boot_quirk(dev);
+        case USB_ID(0x047f, 0xc010): /* Plantronics Gamecom 780 */
+                return snd_usb_gamecon780_boot_quirk(dev);
         }
 
         return 0;