From: Arnd Bergmann <arnd@arndb.de>

The alternative path leads to a build error after a recent change:

sound/pci/hda/patch_realtek.c: In function 'alc233_fixup_lenovo_low_en_micmute_led':
include/linux/stddef.h:9:14: error: called object is not a function or function pointer
    9 | #define NULL ((void *)0)
      |              ^
sound/pci/hda/patch_realtek.c:5041:49: note: in expansion of macro 'NULL'
 5041 | #define alc233_fixup_lenovo_line2_mic_hotkey    NULL
      |                                                 ^~~~
sound/pci/hda/patch_realtek.c:5063:9: note: in expansion of macro 'alc233_fixup_lenovo_line2_mic_hotkey'
 5063 |         alc233_fixup_lenovo_line2_mic_hotkey(codec, fix, action);

Using IS_REACHABLE() is somewhat questionable here anyway since it
leads to the input code not working when the HDA driver is builtin
but input is in a loadable module. Replace this with a hard compile-time
dependency on CONFIG_INPUT. In practice this won't chance much
other than solve the compiler error because it is rare to require
sound output but no input support.

Fixes: f603b159231b ("ALSA: hda/realtek - add supported Mic Mute LED for Lenovo platform")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 sound/pci/hda/Kconfig         | 1 +
 sound/pci/hda/patch_realtek.c | 5 -----
 2 files changed, 1 insertion(+), 5 deletions(-)

diff --git a/sound/pci/hda/Kconfig b/sound/pci/hda/Kconfig
index 9f68cb73b54f..fb955a205d50 100644
--- a/sound/pci/hda/Kconfig
+++ b/sound/pci/hda/Kconfig
@@ -222,6 +222,7 @@ comment "Set to Y if you want auto-loading the side codec driver"
 
 config SND_HDA_CODEC_REALTEK
 	tristate "Build Realtek HD-audio codec support"
+	depends on INPUT
 	select SND_HDA_GENERIC
 	select SND_HDA_GENERIC_LEDS
 	select SND_HDA_SCODEC_COMPONENT
diff --git a/sound/pci/hda/patch_realtek.c b/sound/pci/hda/patch_realtek.c
index ebf54ef5877a..697a38e41e16 100644
--- a/sound/pci/hda/patch_realtek.c
+++ b/sound/pci/hda/patch_realtek.c
@@ -4927,7 +4927,6 @@ static void alc298_fixup_samsung_amp_v2_4_amps(struct hda_codec *codec,
 		alc298_samsung_v2_init_amps(codec, 4);
 }
 
-#if IS_REACHABLE(CONFIG_INPUT)
 static void gpio2_mic_hotkey_event(struct hda_codec *codec,
 				   struct hda_jack_callback *event)
 {
@@ -5036,10 +5035,6 @@ static void alc233_fixup_lenovo_line2_mic_hotkey(struct hda_codec *codec,
 		spec->kb_dev = NULL;
 	}
 }
-#else /* INPUT */
-#define alc280_fixup_hp_gpio2_mic_hotkey	NULL
-#define alc233_fixup_lenovo_line2_mic_hotkey	NULL
-#endif /* INPUT */
 
 static void alc269_fixup_hp_line1_mic1_led(struct hda_codec *codec,
 				const struct hda_fixup *fix, int action)
-- 
2.39.5

On Tue, 04 Mar 2025 15:25:55 +0100,
Arnd Bergmann wrote:
> 
> From: Arnd Bergmann <arnd@arndb.de>
> 
> The alternative path leads to a build error after a recent change:
> 
> sound/pci/hda/patch_realtek.c: In function 'alc233_fixup_lenovo_low_en_micmute_led':
> include/linux/stddef.h:9:14: error: called object is not a function or function pointer
>     9 | #define NULL ((void *)0)
>       |              ^
> sound/pci/hda/patch_realtek.c:5041:49: note: in expansion of macro 'NULL'
>  5041 | #define alc233_fixup_lenovo_line2_mic_hotkey    NULL
>       |                                                 ^~~~
> sound/pci/hda/patch_realtek.c:5063:9: note: in expansion of macro 'alc233_fixup_lenovo_line2_mic_hotkey'
>  5063 |         alc233_fixup_lenovo_line2_mic_hotkey(codec, fix, action);
> 
> Using IS_REACHABLE() is somewhat questionable here anyway since it
> leads to the input code not working when the HDA driver is builtin
> but input is in a loadable module. Replace this with a hard compile-time
> dependency on CONFIG_INPUT. In practice this won't chance much
> other than solve the compiler error because it is rare to require
> sound output but no input support.
> 
> Fixes: f603b159231b ("ALSA: hda/realtek - add supported Mic Mute LED for Lenovo platform")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Thanks for the patch.  Indeed it's a very corner case, but I still
hesitate to add a kconfig dependency.  Can we take an alternative fix
to define the proper dummy functions like below instead?


Takashi

-- 8< --
--- a/sound/pci/hda/patch_realtek.c
+++ b/sound/pci/hda/patch_realtek.c
@@ -5038,8 +5038,21 @@ static void alc233_fixup_lenovo_line2_mic_hotkey(struct hda_codec *codec,
 	}
 }
 #else /* INPUT */
-#define alc280_fixup_hp_gpio2_mic_hotkey	NULL
-#define alc233_fixup_lenovo_line2_mic_hotkey	NULL
+static void alc280_fixup_hp_gpio2_mic_hotkey(struct hda_codec *codec,
+					     const struct hda_fixup *fix,
+					     int action)
+{
+	if (action == HDA_FIXUP_ACT_PRE_PROBE)
+		codec_info(codec, "Input is disabled, skipping quirk\n");
+}
+
+static void alc233_fixup_lenovo_line2_mic_hotkey(struct hda_codec *codec,
+						 const struct hda_fixup *fix,
+						 int action)
+{
+	if (action == HDA_FIXUP_ACT_PRE_PROBE)
+		codec_info(codec, "Input is disabled, skipping quirk\n");
+}
 #endif /* INPUT */
 
 static void alc269_fixup_hp_line1_mic1_led(struct hda_codec *codec,

On Tue, Mar 4, 2025, at 15:43, Takashi Iwai wrote:
> On Tue, 04 Mar 2025 15:25:55 +0100,
>
> Thanks for the patch.  Indeed it's a very corner case, but I still
> hesitate to add a kconfig dependency.  Can we take an alternative fix
> to define the proper dummy functions like below instead?

I'm sure that works, and I had considered something like that,
but I really dislike the IS_REACHABLE() use because I think it
causes more problems than it solves. (I introduced the macro
originally but regret that).

Note that the only way to disable input is to have manually flip
CONFIG_EXPERT and CONFIG_TTY as well as the major GPU drivers
that select it:

config INPUT
        tristate "Generic input layer (needed for keyboard, mouse, ...)" if EXPERT
        default y

so in the end, there is very little difference between
your patch and mine, as they both fix build testing on
randconfig.

    Arnd

On Tue, 04 Mar 2025 15:54:33 +0100,
Arnd Bergmann wrote:
> 
> On Tue, Mar 4, 2025, at 15:43, Takashi Iwai wrote:
> > On Tue, 04 Mar 2025 15:25:55 +0100,
> >
> > Thanks for the patch.  Indeed it's a very corner case, but I still
> > hesitate to add a kconfig dependency.  Can we take an alternative fix
> > to define the proper dummy functions like below instead?
> 
> I'm sure that works, and I had considered something like that,
> but I really dislike the IS_REACHABLE() use because I think it
> causes more problems than it solves. (I introduced the macro
> originally but regret that).
> 
> Note that the only way to disable input is to have manually flip
> CONFIG_EXPERT and CONFIG_TTY as well as the major GPU drivers
> that select it:
> 
> config INPUT
>         tristate "Generic input layer (needed for keyboard, mouse, ...)" if EXPERT
>         default y
> 
> so in the end, there is very little difference between
> your patch and mine, as they both fix build testing on
> randconfig.

OK, I don't mind much, so I take your patch now, as this actually
reduces the code size.


thanks,

Takashi