ALSA: usb-audio: Add dB range mapping for Sennheiser Communications Headset PC 8

The decibel volume range contains a negative maximum value resulting in
pipewire complaining about the device and effectivly having no sound
output. The wrong values also resulted in the headset sounding muted
already at a mixer level of about ~25%.

PipeWire BugLink: https://gitlab.freedesktop.org/pipewire/pipewire/-/issues/1049

BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=212897
Signed-off-by: Timo Gurr <[email protected]>
Cc: <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Takashi Iwai <[email protected]>

Author: tgurr

sound/usb/mixer_maps.c

@@ -337,6 +337,13 @@ static const struct usbmix_name_map bose_companion5_map[] = {
 	{ 0 }	/* terminator */
 };
 
+/* Sennheiser Communications Headset [PC 8], the dB value is reported as -6 negative maximum  */
+static const struct usbmix_dB_map sennheiser_pc8_dB = {-9500, 0};
+static const struct usbmix_name_map sennheiser_pc8_map[] = {
+	{ 9, NULL, .dB = &sennheiser_pc8_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
@@ -593,6 +600,11 @@ static const struct usbmix_ctl_map usbmix_ctl_maps[] = {
 		.id = USB_ID(0x17aa, 0x1046),
 		.map = lenovo_p620_rear_map,
 	},
+	{
+		/* Sennheiser Communications Headset [PC 8] */
+		.id = USB_ID(0x1395, 0x0025),
+		.map = sennheiser_pc8_map,
+	},
 	{ 0 } /* terminator */
 };