volume: fix scaling function reset after max volume

Fix a generic issue where the scale_vol function pointer is not reset
after volume reaches its maximum value. When volume hits max,
is_passthrough is set to true and scale_vol points to the passthrough
function. On subsequent volume decreases, is_passthrough remains set
and the correct gain function is never re-selected, so the volume
change has no audible effect.

Fix by resetting is_passthrough to false and re-selecting scale_vol
via set_volume_process() on every SOF_CTRL_CMD_VOLUME command,
ensuring correct volume scaling in both directions.

Signed-off-by: Sneha Voona <sneha.voona@amd.com>

Author: sneha-voona

src/audio/volume/volume_ipc3.c

@@ -219,6 +219,11 @@ int volume_set_config(struct processing_module *mod, uint32_t config_id,
 		volume_set_ramp_channel_counter(cd, cd->channels);
 
 		volume_ramp_check(mod);
+		/* Update function pointer after all volume changes */
+		if (comp_dev_get_first_data_consumer(dev) != NULL) {
+			cd->is_passthrough = false;
+			set_volume_process(cd, dev, false);
+		}
 		break;
 
 	case SOF_CTRL_CMD_SWITCH: