Messages in this thread | | | From | Guenter Roeck <> | Date | Tue, 19 Jul 2022 12:31:40 -0700 | Subject | Re: [PATCH v2] platform/chrome: cros_kbd_led_backlight: fix build warning |
| |
On Mon, Jul 18, 2022 at 9:54 PM Tzung-Bi Shih <tzungbi@kernel.org> wrote: > > On Mon, Jul 18, 2022 at 06:28:22AM -0700, Guenter Roeck wrote: > > On Mon, Jul 18, 2022 at 3:51 AM Tzung-Bi Shih <tzungbi@kernel.org> wrote: > > > > > > drivers/platform/chrome/cros_kbd_led_backlight.c got a new build warning > > > when using the randconfig in [1]: > > > >>> warning: unused variable 'keyboard_led_drvdata_ec_pwm' > > > > > > The warning happens when CONFIG_CROS_EC is set but CONFIG_OF is not set. > > > Reproduce: > > > - mkdir build_dir > > > - wget [1] -O build_dir/.config > > > - COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 \ > > > O=build_dir ARCH=s390 SHELL=/bin/bash drivers/platform/chrome/ > > > > > > Fix the warning by using __maybe_unused. Also use IS_ENABLED() because > > > CROS_EC is a tristate. > > > > Is that sufficient ? What happens if CROS_KBD_LED_BACKLIGHT=y and > > CROS_EC=m ? I suspect you might need IS_REACHABLE() instead of > > IS_ENABLED(). > > For current code, it's impossible to set CROS_KBD_LED_BACKLIGHT=y and > CROS_EC=m without setting ACPI=y. Given that the dependencies: > CHROME_PLATFORMS [=y] && LEDS_CLASS [=y] && (ACPI [=n] || CROS_EC [=m]). > > $ ./scripts/kconfig/merge_config.sh -n <(cat <<EOF > CONFIG_MODULES=y > > CONFIG_NEW_LEDS=y > CONFIG_LEDS_CLASS=y > > CONFIG_CHROME_PLATFORMS=y > CONFIG_CROS_EC=m > CONFIG_CROS_KBD_LED_BACKLIGHT=y > EOF > ) > [...] > Value requested for CONFIG_CROS_KBD_LED_BACKLIGHT not in final .config > Requested value: CONFIG_CROS_KBD_LED_BACKLIGHT=y > Actual value: CONFIG_CROS_KBD_LED_BACKLIGHT=m >
It is actually possible to configure CONFIG_CROS_KBD_LED_BACKLIGHT=y with CONFIG_CROS_EC=m, by also setting CONFIG_LEDS_CLASS=y. However, that doesn't seem to matter since the critical symbol is CROS_EC_PROTO which is boolean. Given that, IS_ENABLED should be fine.
Reviewed-by: Guenter Roeck <groeck@chromium.org>
Thanks, Guenter
> However, when ACPI=y, `keyboard_led_drvdata_ec_pwm` is unused. Instead, it > uses `keyboard_led_drvdata_acpi` for current code. > > I guess IS_ENABLED() is sufficient. Does it make sense?
| |