Re: [PATCH] ath9k: fix build error with LEDS_CLASS=m

[Krzysztof Kozlowski <krzk@kernel.org>]

On Mon, 25 Jan 2021 at 12:36, Arnd Bergmann <arnd@kernel.org> wrote:
>
> From: Arnd Bergmann <arnd@arndb.de>
>
> When CONFIG_ATH9K is built-in but LED support is in a loadable
> module, both ath9k drivers fails to link:
>
> x86_64-linux-ld: drivers/net/wireless/ath/ath9k/gpio.o: in function `ath_deinit_leds':
> gpio.c:(.text+0x36): undefined reference to `led_classdev_unregister'
> x86_64-linux-ld: drivers/net/wireless/ath/ath9k/gpio.o: in function `ath_init_leds':
> gpio.c:(.text+0x179): undefined reference to `led_classdev_register_ext'
>
> The problem is that the 'imply' keyword does not enforce any dependency
> but is only a weak hint to Kconfig to enable another symbol from a
> defconfig file.
>
> Change imply to a 'depends on LEDS_CLASS' that prevents the incorrect
> configuration but still allows building the driver without LED support.
>
> The 'select MAC80211_LEDS' is now ensures that the LED support is
> actually used if it is present, and the added Kconfig dependency
> on MAC80211_LEDS ensures that it cannot be enabled manually when it
> has no effect.

But we do not want to have this dependency (selecting MAC80211_LEDS).
I fixed this problem here:
https://lore.kernel.org/lkml/20201227143034.1134829-1-krzk@kernel.org/
Maybe let's take this approach?

Best regards,
Krzysztof

>
> Fixes: 197f466e93f5 ("ath9k_htc: Do not select MAC80211_LEDS by default")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
>  drivers/net/wireless/ath/ath9k/Kconfig | 8 ++------
>  net/mac80211/Kconfig                   | 2 +-
>  2 files changed, 3 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/net/wireless/ath/ath9k/Kconfig b/drivers/net/wireless/ath/ath9k/Kconfig
> index a84bb9b6573f..e150d82eddb6 100644
> --- a/drivers/net/wireless/ath/ath9k/Kconfig
> +++ b/drivers/net/wireless/ath/ath9k/Kconfig
> @@ -21,11 +21,9 @@ config ATH9K_BTCOEX_SUPPORT
>  config ATH9K
>         tristate "Atheros 802.11n wireless cards support"
>         depends on MAC80211 && HAS_DMA
> +       select MAC80211_LEDS if LEDS_CLASS=y || LEDS_CLASS=MAC80211
>         select ATH9K_HW
>         select ATH9K_COMMON
> -       imply NEW_LEDS
> -       imply LEDS_CLASS
> -       imply MAC80211_LEDS
>         help
>           This module adds support for wireless adapters based on
>           Atheros IEEE 802.11n AR5008, AR9001 and AR9002 family
> @@ -176,11 +174,9 @@ config ATH9K_PCI_NO_EEPROM
>  config ATH9K_HTC
>         tristate "Atheros HTC based wireless cards support"
>         depends on USB && MAC80211
> +       select MAC80211_LEDS if LEDS_CLASS=y || LEDS_CLASS=MAC80211
>         select ATH9K_HW
>         select ATH9K_COMMON
> -       imply NEW_LEDS
> -       imply LEDS_CLASS
> -       imply MAC80211_LEDS
>         help
>           Support for Atheros HTC based cards.
>           Chipsets supported: AR9271
> diff --git a/net/mac80211/Kconfig b/net/mac80211/Kconfig
> index cd9a9bd242ba..51ec8256b7fa 100644
> --- a/net/mac80211/Kconfig
> +++ b/net/mac80211/Kconfig
> @@ -69,7 +69,7 @@ config MAC80211_MESH
>  config MAC80211_LEDS
>         bool "Enable LED triggers"
>         depends on MAC80211
> -       depends on LEDS_CLASS
> +       depends on LEDS_CLASS=y || LEDS_CLASS=MAC80211
>         select LEDS_TRIGGERS
>         help
>           This option enables a few LED triggers for different
> --
> 2.29.2
>