This is an attempt to make a recurring kconfig issue more visible:
select statements for unknown, or unreachable, Kconfig symbols. See,
I've submitted quite a few patches that remove statements like
select BOGUS
One of the annoying properties of kconfig is that select statements like
that are silently treated as a nop. That makes them surprisingly easy to
stay unnoticed. Some of them are caught by my local "800 line perl
monster", but not all. But perhaps silently skipping these statements is
actually considered a feature. I think it is not.
Anyhow, I've tweaked kconfig to warn about them. Then I ran kconfig on
all (500+) in tree defconfig files as of next-20140930. These are the
select statements it warns about when doing that.
The most interesting are 8 (CPU_IDLE), 10 (PREEMPT_COUNT) and 11
(ZONE_DMA).
1) arch/arm/Kconfig:429:warning: 'ARCH_EFM32' selects unknown symbol 'NO_DMA'
Unknown on arm. Patch submitted.
2) arch/arm/mach-meson/Kconfig:11:warning: 'MACH_MESON6' selects unknown symbol 'MESON6_TIMER'
Clearly bogus select. But Kconfig symbol MESON6_TIMER is apparently
queued.
3) arch/arm/mach-mvebu/Kconfig:40:warning: 'MACH_ARMADA_375' selects unknown symbol 'ARM_ERRATA_753970'
arch/arm/mach-mvebu/Kconfig:55:warning: 'MACH_ARMADA_38X' selects unknown symbol 'ARM_ERRATA_753970'
Typo. Patch is being discussed for some time now.
4) arch/arm/mach-shmobile/Kconfig:39:warning: 'ARCH_SHMOBILE_MULTI' selects unknown symbol 'ARCH_HAS_OPP'
Unfinished Kconfig cleanup. Patches submitted and/or queued.
5) arch/hexagon/Kconfig:22:warning: 'HEXAGON' selects unknown symbol 'NO_IOPORT_MAP'
Unknown on hexagon. Patch submitted and already Acked.
6) arch/powerpc/platforms/44x/Kconfig:217:warning: 'AKEBONO' selects unknown symbol 'IBM_EMAC_RGMII_WOL'
arch/powerpc/platforms/44x/Kconfig:223:warning: 'AKEBONO' selects unknown symbol 'MMC_SDHCI_OF_476GTR'
Clearly bogus selects. One symbol might be queued. Not sure why the
other select hasn't been removed.
7) arch/score/Kconfig:24:warning: 'ARCH_SCORE7' selects unknown symbol 'SYS_SUPPORTS_32BIT_KERNEL'
arch/score/Kconfig:28:warning: 'MACH_SPCT6600' selects unknown symbol 'SYS_SUPPORTS_32BIT_KERNEL'
arch/score/Kconfig:32:warning: 'SCORE_SIM' selects unknown symbol 'SYS_SUPPORTS_32BIT_KERNEL'
Bogus. Submitted a patch long ago. Nothing happened.
8) drivers/acpi/Kconfig:165:warning: 'ACPI_PROCESSOR' selects unknown symbol 'CPU_IDLE'
Unreachable for eg ia64. Perhaps fixed by:
--- a/drivers/acpi/Kconfig
+++ b/drivers/acpi/Kconfig
@@ -162,7 +162,7 @@ config ACPI_DOCK
config ACPI_PROCESSOR
tristate "Processor"
select THERMAL
- select CPU_IDLE
+ select CPU_IDLE if (ARM || ARM64 || MIPS || PPC || X86 || SUPERH)
default y
help
This driver installs ACPI as the idle handler for Linux and uses
9) drivers/irqchip/Kconfig:16:warning: 'ARM_GIC_V3' selects unknown symbol 'MULTI_IRQ_HANDLER'
drivers/irqchip/Kconfig:8:warning: 'ARM_GIC' selects unknown symbol 'MULTI_IRQ_HANDLER'
MULTI_IRQ_HANDLER is arm specific. So arm64 builds trigger this.
Suggested fix:
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -5,7 +5,7 @@ config IRQCHIP
config ARM_GIC
bool
select IRQ_DOMAIN
- select MULTI_IRQ_HANDLER
+ select MULTI_IRQ_HANDLER if ARM
config GIC_NON_BANKED
bool
@@ -13,7 +13,6 @@ config GIC_NON_BANKED
config ARM_GIC_V3
bool
select IRQ_DOMAIN
- select MULTI_IRQ_HANDLER
config ARM_NVIC
bool
10) lib/Kconfig.debug:1008:warning: 'DEBUG_ATOMIC_SLEEP' selects unknown symbol 'PREEMPT_COUNT'
Not all architectures have PREEMPT_COUNT. Maybe fixed by:
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1005,7 +1005,7 @@ config DEBUG_LOCKDEP
config DEBUG_ATOMIC_SLEEP
bool "Sleep inside atomic section checking"
- select PREEMPT_COUNT
+ select PREEMPT_COUNT if !(ALPHA || FRV || HEXAGON || UML)
depends on DEBUG_KERNEL
help
If you say Y here, various routines which may sleep will become very
Not sure, however.
11) sound/pci/Kconfig:158:warning: 'SND_AZT3328' selects unknown symbol 'ZONE_DMA'
sound/pci/Kconfig:28:warning: 'SND_ALS300' selects unknown symbol 'ZONE_DMA'
sound/pci/Kconfig:466:warning: 'SND_EMU10K1' selects unknown symbol 'ZONE_DMA'
sound/pci/Kconfig:482:warning: 'SND_EMU10K1X' selects unknown symbol 'ZONE_DMA'
sound/pci/Kconfig:516:warning: 'SND_ES1938' selects unknown symbol 'ZONE_DMA'
sound/pci/Kconfig:528:warning: 'SND_ES1968' selects unknown symbol 'ZONE_DMA'
sound/pci/Kconfig:53:warning: 'SND_ALI5451' selects unknown symbol 'ZONE_DMA'
sound/pci/Kconfig:615:warning: 'SND_ICE1712' selects unknown symbol 'ZONE_DMA'
sound/pci/Kconfig:703:warning: 'SND_MAESTRO3' selects unknown symbol 'ZONE_DMA'
sound/pci/Kconfig:812:warning: 'SND_SONICVIBES' selects unknown symbol 'ZONE_DMA'
sound/pci/Kconfig:824:warning: 'SND_TRIDENT' selects unknown symbol 'ZONE_DMA'
Seen on parisc and sh. Tricky. See commit 80ab8eae70e5 ("ALSA: Enable
CONFIG_ZONE_DMA for smaller PCI DMA masks"). Nice quote from Andrew
Morton about adding these selects (instead of fixing the underlying
problem):
But then we'll just forget about it :(
(https://bugzilla.kernel.org/show_bug.cgi?id=68221#c19 ).
Comments welcome!
Paul Bolle (1):
kconfig: warn if an unknown symbol is selected
scripts/kconfig/conf.c | 41 +++++++++++++++++++++++++++++++++++++++++
1 file changed, 41 insertions(+)
--
1.9.3
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