From: Arnd Bergmann arnd@arndb.de
[ Upstream commit dfd6f9ad36368b8dbd5f5a2b2f0a4705ae69a323 ]
clang gets confused by an uninitialized variable in what looks to it like a never executed code path:
arch/x86/kernel/acpi/boot.c:618:13: error: variable 'polarity' is uninitialized when used here [-Werror,-Wuninitialized] polarity = polarity ? ACPI_ACTIVE_LOW : ACPI_ACTIVE_HIGH; ^~~~~~~~ arch/x86/kernel/acpi/boot.c:606:32: note: initialize the variable 'polarity' to silence this warning int rc, irq, trigger, polarity; ^ = 0 arch/x86/kernel/acpi/boot.c:617:12: error: variable 'trigger' is uninitialized when used here [-Werror,-Wuninitialized] trigger = trigger ? ACPI_LEVEL_SENSITIVE : ACPI_EDGE_SENSITIVE; ^~~~~~~ arch/x86/kernel/acpi/boot.c:606:22: note: initialize the variable 'trigger' to silence this warning int rc, irq, trigger, polarity; ^ = 0
This is unfortunately a design decision in clang and won't be fixed.
Changing the acpi_get_override_irq() macro to an inline function reliably avoids the issue.
Signed-off-by: Arnd Bergmann arnd@arndb.de Reviewed-by: Andy Shevchenko andriy.shevchenko@linux.intel.com Reviewed-by: Nathan Chancellor natechancellor@gmail.com Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- include/linux/acpi.h | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/include/linux/acpi.h b/include/linux/acpi.h index ca2b4c4aec42..719eb97217a3 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -309,7 +309,10 @@ void acpi_set_irq_model(enum acpi_irq_model_id model, #ifdef CONFIG_X86_IO_APIC extern int acpi_get_override_irq(u32 gsi, int *trigger, int *polarity); #else -#define acpi_get_override_irq(gsi, trigger, polarity) (-1) +static inline int acpi_get_override_irq(u32 gsi, int *trigger, int *polarity) +{ + return -1; +} #endif /* * This function undoes the effect of one call to acpi_register_gsi().