[PATCH 13/39] x86: intel_epb: Don't rely on link order

Russell King (Oracle) <[email protected]>
Newsgroups gmane.linux.acpi.devel,gmane.linux.power-management.general,gmane.linux.kernel.cross-arch,gmane.linux.kernel,gmane.linux.ports.arm.kernel,gmane.linux.ports.riscv,gmane.linux.documentation,gmane.linux.ports.ia64,gmane.linux.ports.parisc
Message-ID <[email protected]>
From: James Morse <[email protected]>

intel_epb_init() is called as a subsys_initcall() to register cpuhp
callbacks. The callbacks make use of get_cpu_device() which will return
NULL unless register_cpu() has been called. register_cpu() is called
from topology_init(), which is also a subsys_initcall().

This is fragile. Moving the register_cpu() to a different
subsys_initcall()  leads to a NULL dereference during boot.

Make intel_epb_init() a late_initcall(), user-space can't provide a
policy before this point anyway.

Signed-off-by: James Morse <[email protected]>
Signed-off-by: Russell King (Oracle) <[email protected]>
---
subsys_initcall_sync() would be an option, but moving the register_cpu()
calls into ACPI also means adding a safety net for CPUs that are online
but not described properly by firmware. This lives in subsys_initcall_sync().
---
 arch/x86/kernel/cpu/intel_epb.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kernel/cpu/intel_epb.c b/arch/x86/kernel/cpu/intel_epb.c
index e4c3ba91321c..f18d35fe27a9 100644
--- a/arch/x86/kernel/cpu/intel_epb.c
+++ b/arch/x86/kernel/cpu/intel_epb.c
@@ -237,4 +237,4 @@ static __init int intel_epb_init(void)
 	cpuhp_remove_state(CPUHP_AP_X86_INTEL_EPB_ONLINE);
 	return ret;
 }
-subsys_initcall(intel_epb_init);
+late_initcall(intel_epb_init);
-- 
2.30.2
lmpx.com only provides a reader for public news (NNTP) servers. It is not affiliated with the servers or forums shown here and is not responsible for the content of articles, which is written by their respective authors.