git: a7cf142ba904 - stable/15 - acpi_apm: Narrow scope of ACPI_LOCK

The branch stable/15 has been updated by jhb:

URL: https://cgit.FreeBSD.org/src/commit/?id=a7cf142ba9044c3b8f88b4a8ed7f5720bc39b90c

commit a7cf142ba9044c3b8f88b4a8ed7f5720bc39b90c
Author:     John Baldwin <jhb@FreeBSD.org>
AuthorDate: 2026-03-30 13:38:54 +0000
Commit:     John Baldwin <jhb@FreeBSD.org>
CommitDate: 2026-04-24 17:49:14 +0000

    acpi_apm: Narrow scope of ACPI_LOCK
    
    This lock doesn't need to be held across seldrain/knlist_destroy.  It
    is also redundant (and a bug) to hold it across knlist_add and
    knlist_remove since it is the mutex for the knlist.
    
    PR:             293901
    Reported by:    Jiaming Zhang <r772577952@gmail.com>
    Reviewed by:    markj
    MFC after:      1 week
    Differential Revision:  https://reviews.freebsd.org/D55994
    
    (cherry picked from commit cc2715cf1f864345ab175db691d4e152d5fb84af)
---
 sys/x86/acpica/acpi_apm.c | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/sys/x86/acpica/acpi_apm.c b/sys/x86/acpica/acpi_apm.c
index d5fee124703d..74987ad01d0d 100644
--- a/sys/x86/acpica/acpi_apm.c
+++ b/sys/x86/acpica/acpi_apm.c
@@ -243,9 +243,9 @@ apmdtor(void *data)
 	/* Remove this clone's data from the list and free it. */
 	ACPI_LOCK(acpi);
 	STAILQ_REMOVE(&acpi_sc->apm_cdevs, clone, apm_clone_data, entries);
+	ACPI_UNLOCK(acpi);
 	seldrain(&clone->sel_read);
 	knlist_destroy(&clone->sel_read.si_note);
-	ACPI_UNLOCK(acpi);
 	free(clone, M_APMDEV);
 }
 
@@ -407,11 +407,9 @@ apmkqfilter(struct cdev *dev, struct knote *kn)
 	struct	apm_clone_data *clone;
 
 	devfs_get_cdevpriv((void **)&clone);
-	ACPI_LOCK(acpi);
 	kn->kn_hook = clone;
 	kn->kn_fop = &apm_readfiltops;
 	knlist_add(&clone->sel_read.si_note, kn, 0);
-	ACPI_UNLOCK(acpi);
 	return (0);
 }
 
@@ -420,10 +418,8 @@ apmreadfiltdetach(struct knote *kn)
 {
 	struct	apm_clone_data *clone;
 
-	ACPI_LOCK(acpi);
 	clone = kn->kn_hook;
 	knlist_remove(&clone->sel_read.si_note, kn, 0);
-	ACPI_UNLOCK(acpi);
 }
 
 static int
@@ -432,8 +428,8 @@ apmreadfilt(struct knote *kn, long hint)
 	struct	apm_clone_data *clone;
 	int	sleeping;
 
-	ACPI_LOCK(acpi);
 	clone = kn->kn_hook;
+	ACPI_LOCK(acpi);
 	sleeping = clone->acpi_sc->acpi_next_sstate ? 1 : 0;
 	ACPI_UNLOCK(acpi);
 	return (sleeping);