drm/meson: Add AFBCD module driver

[linux.git] / block / elevator.c

diff --git a/block/elevator.c b/block/elevator.c
index bba10e83478a0902dc883e7924a6f5cb66bec83b..076ba7308e65c34a8e4abd1df484d7388b8a4494 100644 (file)
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -503,9 +503,7 @@ int elv_register_queue(struct request_queue *q, bool uevent)
                if (uevent)
                        kobject_uevent(&e->kobj, KOBJ_ADD);
 
-               mutex_lock(&q->sysfs_lock);
                e->registered = 1;
-               mutex_unlock(&q->sysfs_lock);
        }
        return error;
 }
@@ -523,11 +521,9 @@ void elv_unregister_queue(struct request_queue *q)
                kobject_uevent(&e->kobj, KOBJ_REMOVE);
                kobject_del(&e->kobj);
 
-               mutex_lock(&q->sysfs_lock);
                e->registered = 0;
                /* Re-enable throttling in case elevator disabled it */
                wbt_enable_default(q);
-               mutex_unlock(&q->sysfs_lock);
        }
 }
 
@@ -590,32 +586,11 @@ int elevator_switch_mq(struct request_queue *q,
        lockdep_assert_held(&q->sysfs_lock);
 
        if (q->elevator) {
-               if (q->elevator->registered) {
-                       mutex_unlock(&q->sysfs_lock);
-
-                       /*
-                        * Concurrent elevator switch can't happen becasue
-                        * sysfs write is always exclusively on same file.
-                        *
-                        * Also the elevator queue won't be freed after
-                        * sysfs_lock is released becasue kobject_del() in
-                        * blk_unregister_queue() waits for completion of
-                        * .store & .show on its attributes.
-                        */
+               if (q->elevator->registered)
                        elv_unregister_queue(q);
 
-                       mutex_lock(&q->sysfs_lock);
-               }
                ioc_clear_queue(q);
                elevator_exit(q, q->elevator);
-
-               /*
-                * sysfs_lock may be dropped, so re-check if queue is
-                * unregistered. If yes, don't switch to new elevator
-                * any more
-                */
-               if (!blk_queue_registered(q))
-                       return 0;
        }
 
        ret = blk_mq_init_sched(q, new_e);
@@ -623,11 +598,7 @@ int elevator_switch_mq(struct request_queue *q,
                goto out;
 
        if (new_e) {
-               mutex_unlock(&q->sysfs_lock);
-
                ret = elv_register_queue(q, true);
-
-               mutex_lock(&q->sysfs_lock);
                if (ret) {
                        elevator_exit(q, q->elevator);
                        goto out;
@@ -645,7 +616,8 @@ int elevator_switch_mq(struct request_queue *q,
 
 static inline bool elv_support_iosched(struct request_queue *q)
 {
-       if (q->tag_set && (q->tag_set->flags & BLK_MQ_F_NO_SCHED))
+       if (!q->mq_ops ||
+           (q->tag_set && (q->tag_set->flags & BLK_MQ_F_NO_SCHED)))
                return false;
        return true;
 }