diff options
| author | David Hildenbrand <david@redhat.com> | 2019-08-02 21:49:29 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-08-03 07:02:01 -0700 |
| commit | 7291edca20215dfdf0eb841881d63753448ef09c (patch) | |
| tree | 2b2f073b22efdeb09e02cb8391b015ee22292b8d | |
| parent | 14c5cebad510c2875ca525f36605b47058769670 (diff) | |
| download | lwn-7291edca20215dfdf0eb841881d63753448ef09c.tar.gz lwn-7291edca20215dfdf0eb841881d63753448ef09c.zip | |
drivers/acpi/scan.c: document why we don't need the device_hotplug_lock
Let's document why the lock is not needed in acpi_scan_init(), right now
this is not really obvious.
[akpm@linux-foundation.org: fix tpyo]
Link: http://lkml.kernel.org/r/20190731135306.31524-1-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | drivers/acpi/scan.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index 0e28270b0fd8..aad6be5c0af0 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -2204,6 +2204,12 @@ int __init acpi_scan_init(void) acpi_gpe_apply_masked_gpes(); acpi_update_all_gpes(); + /* + * Although we call __add_memory() that is documented to require the + * device_hotplug_lock, it is not necessary here because this is an + * early code when userspace or any other code path cannot trigger + * hotplug/hotunplug operations. + */ mutex_lock(&acpi_scan_lock); /* * Enumerate devices in the ACPI namespace. |