When CROS_EC_LPC is set to =m, we get a link failure for a builtin wilco-ec module:
drivers/platform/chrome/wilco_ec/core.o: In function `wilco_ec_remove': core.c:(.text+0x26): undefined reference to `cros_ec_lpc_mec_destroy' drivers/platform/chrome/wilco_ec/core.o: In function `wilco_ec_probe': core.c:(.text+0x18c): undefined reference to `cros_ec_lpc_mec_init' core.c:(.text+0x224): undefined reference to `cros_ec_lpc_mec_destroy' drivers/platform/chrome/wilco_ec/mailbox.o: In function `wilco_ec_mailbox': mailbox.c:(.text+0x104): undefined reference to `cros_ec_lpc_io_bytes_mec' The problem with the existing CROS_EC_LPC_MEC dependency is that this is only for a 'bool' symbol, so the information about the exported functions being in a module is lost on the way, and we actually have to depend on both CROS_EC_LPC and CROS_EC_LPC_MEC. Fixes: 7b3d4f44abf0 ("platform/chrome: Add new driver for Wilco EC") Signed-off-by: Arnd Bergmann <a...@arndb.de> --- drivers/platform/chrome/wilco_ec/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/platform/chrome/wilco_ec/Kconfig b/drivers/platform/chrome/wilco_ec/Kconfig index 4a119ced4d0c..e09e4cebe9b4 100644 --- a/drivers/platform/chrome/wilco_ec/Kconfig +++ b/drivers/platform/chrome/wilco_ec/Kconfig @@ -1,6 +1,6 @@ config WILCO_EC tristate "ChromeOS Wilco Embedded Controller" - depends on ACPI && X86 && CROS_EC_LPC_MEC + depends on ACPI && X86 && CROS_EC_LPC && CROS_EC_LPC_MEC help If you say Y here, you get support for talking to the ChromeOS Wilco EC over an eSPI bus. This uses a simple byte-level protocol -- 2.20.0