src/kernel/linux/v4.19/drivers/misc/echo/Kconfig - T800 - Gitiles

 config ECHO
 	tristate "Line Echo Canceller support"
 	default n
 	---help---
 	  This driver provides line echo cancelling support for mISDN and
 	  Zaptel drivers.

 	  To compile this driver as a module, choose M here. The module
 	  will be called echo.
	config ECHO
	tristate "Line Echo Canceller support"
	default n
	---help---
	This driver provides line echo cancelling support for mISDN and
	Zaptel drivers.

	To compile this driver as a module, choose M here. The module
	will be called echo.