[PATCH] wifi: mt76: fix airoha_npu dependency tracking

[PATCH] wifi: mt76: fix airoha_npu dependency tracking

[Arnd Bergmann]

From: Arnd Bergmann <arnd@arndb.de>

There is a new build failure with MT7996E=m MT76_CORE=y and NET_AIROHA_NPU=m:

ld.lld: error: undefined symbol: airoha_npu_get
ld.lld: error: undefined symbol: airoha_npu_put
>>> referenced by npu.c
>>>               drivers/net/wireless/mediatek/mt76/npu.o:(mt76_npu_init) in archive vmlinux.a

Fix this by reworking the dependency for the MT7996_NPU to only
allow enabling that when mt76_core can link against the npu driver.

To make sure this gets caught more easily in the future when additional
mt76 variants need the same dependency, also turn CONFIG_MT76_NPU into
a tristate symbol that has the same dependency.

Fixes: 7fb554b1b623 ("wifi: mt76: Introduce the NPU generic layer")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 drivers/net/wireless/mediatek/mt76/Kconfig        | 4 ++--
 drivers/net/wireless/mediatek/mt76/Makefile       | 6 +++++-
 drivers/net/wireless/mediatek/mt76/mt76.h         | 2 +-
 drivers/net/wireless/mediatek/mt76/mt7996/Kconfig | 2 +-
 4 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/drivers/net/wireless/mediatek/mt76/Kconfig b/drivers/net/wireless/mediatek/mt76/Kconfig
index 502303622a53..d941e67a222d 100644
--- a/drivers/net/wireless/mediatek/mt76/Kconfig
+++ b/drivers/net/wireless/mediatek/mt76/Kconfig
@@ -38,8 +38,8 @@ config MT792x_USB
 	select MT76_USB
 
 config MT76_NPU
-	bool
-	depends on MT76_CORE
+	tristate
+	depends on NET_AIROHA_NPU=y || MT76=NET_AIROHA_NPU
 
 source "drivers/net/wireless/mediatek/mt76/mt76x0/Kconfig"
 source "drivers/net/wireless/mediatek/mt76/mt76x2/Kconfig"
diff --git a/drivers/net/wireless/mediatek/mt76/Makefile b/drivers/net/wireless/mediatek/mt76/Makefile
index 1d42adfe8030..cacdd2b13d05 100644
--- a/drivers/net/wireless/mediatek/mt76/Makefile
+++ b/drivers/net/wireless/mediatek/mt76/Makefile
@@ -12,7 +12,11 @@ mt76-y := \
 	mmio.o util.o trace.o dma.o mac80211.o debugfs.o eeprom.o \
 	tx.o agg-rx.o mcu.o wed.o scan.o channel.o
 
-mt76-$(CONFIG_MT76_NPU) += npu.o
+ifdef CONFIG_MT76_NPU
+# CONFIG_MT76_NPU is tristate to simplify dependency tracking,
+# but it behaves as a bool symbol here.
+mt76-y += npu.o
+endif
 mt76-$(CONFIG_PCI) += pci.o
 mt76-$(CONFIG_NL80211_TESTMODE) += testmode.o
 
diff --git a/drivers/net/wireless/mediatek/mt76/mt76.h b/drivers/net/wireless/mediatek/mt76/mt76.h
index 07955555f84d..60bd155cc7d5 100644
--- a/drivers/net/wireless/mediatek/mt76/mt76.h
+++ b/drivers/net/wireless/mediatek/mt76/mt76.h
@@ -1647,7 +1647,7 @@ int mt76_testmode_dump(struct ieee80211_hw *hw, struct sk_buff *skb,
 int mt76_testmode_set_state(struct mt76_phy *phy, enum mt76_testmode_state state);
 int mt76_testmode_alloc_skb(struct mt76_phy *phy, u32 len);
 
-#ifdef CONFIG_MT76_NPU
+#if IS_ENABLED(CONFIG_MT76_NPU)
 void mt76_npu_check_ppe(struct mt76_dev *dev, struct sk_buff *skb,
 			u32 info);
 int mt76_npu_dma_add_buf(struct mt76_phy *phy, struct mt76_queue *q,
diff --git a/drivers/net/wireless/mediatek/mt76/mt7996/Kconfig b/drivers/net/wireless/mediatek/mt76/mt7996/Kconfig
index 5503d03bf62c..5742bce12fbb 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7996/Kconfig
+++ b/drivers/net/wireless/mediatek/mt76/mt7996/Kconfig
@@ -16,6 +16,6 @@ config MT7996E
 config MT7996_NPU
 	bool "MT7996 (PCIe) NPU support"
 	depends on MT7996E
-	depends on NET_AIROHA_NPU=y || MT7996E=NET_AIROHA_NPU
+	depends on NET_AIROHA_NPU=y || MT76_CORE=NET_AIROHA_NPU
 	select MT76_NPU
 	default n
-- 
2.39.5