[PATCH] platform/chrome: fix wilco-ec dependencies

[PATCH] platform/chrome: fix wilco-ec dependencies

[Arnd Bergmann]

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 <arnd@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

Re: [PATCH] platform/chrome: fix wilco-ec dependencies

[Nick Crews]

On Mon, Mar 4, 2019 at 1:06 PM Arnd Bergmann <arnd@arndb.de> wrote:
>
> 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.

Thanks for the catch Arnd. This looks like a workable solution, although it
brings up a different question to me: Is it weird for a bool option
(such as CROS_EC_LPC_MEC)
to depend upon a tristate option (such as CROS_EC_LPC)? It seems like
CROS_EC_LPC_MEC
should be tristate as well. Would changing this be a better solution?

>
> Fixes: 7b3d4f44abf0 ("platform/chrome: Add new driver for Wilco EC")
> Signed-off-by: Arnd Bergmann <arnd@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
>

Re: [PATCH] platform/chrome: fix wilco-ec dependencies

[Arnd Bergmann]

On Tue, Mar 5, 2019 at 1:53 AM Nick Crews <ncrews@chromium.org> wrote:
>
> On Mon, Mar 4, 2019 at 1:06 PM Arnd Bergmann <arnd@arndb.de> wrote:
> >
> > 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.
>
> Thanks for the catch Arnd. This looks like a workable solution, although it
> brings up a different question to me: Is it weird for a bool option
> (such as CROS_EC_LPC_MEC)
> to depend upon a tristate option (such as CROS_EC_LPC)?

No, not weird at all.

> It seems like
> CROS_EC_LPC_MEC
> should be tristate as well. Would changing this be a better solution?

No, that would actually break the code in a different way, since you
have:

drivers/platform/chrome/Makefile:cros_ec_lpcs-$(CONFIG_CROS_EC_LPC_MEC)
+= cros_ec_lpc_mec.o
drivers/platform/chrome/cros_ec_lpc_reg.c:#ifdef CONFIG_CROS_EC_LPC_MEC
drivers/platform/chrome/cros_ec_lpc_reg.c:#else /* CONFIG_CROS_EC_LPC_MEC */
drivers/platform/chrome/cros_ec_lpc_reg.c:#endif /* CONFIG_CROS_EC_LPC_MEC */

With CONFIG_CROS_EC_LPC_MEC=m, it would not get used
(CONFIG_CROS_EC_LPC_MEC ends up not defined in C code),
and it makes no sense to include a .o file in a loadable module
based on a tristate option.

       Arnd

Re: [PATCH] platform/chrome: fix wilco-ec dependencies

[Enric Balletbo i Serra]

Hi,

On 4/3/19 21:06, Arnd Bergmann wrote:
> 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 <arnd@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
> 

Applied as a fix to our chrome-platform-5.1 branch.

Thanks,
 Enric