8 files changed, 45 insertions, 27 deletions

diff --git a/drivers/gpu/drm/nouveau/nvkm/core/object.c b/drivers/gpu/drm/nouveau/nvkm/core/object.c
index 89d2e9da11c7..acd76fd4f6d8 100644
--- a/drivers/gpu/drm/nouveau/nvkm/core/object.c
+++ b/drivers/gpu/drm/nouveau/nvkm/core/object.c
@@ -295,7 +295,7 @@ nvkm_object_ctor(const struct nvkm_object_func *func,
         INIT_LIST_HEAD(&object->head);
         INIT_LIST_HEAD(&object->tree);
         RB_CLEAR_NODE(&object->node);
-        WARN_ON(oclass->engine && !object->engine);
+        WARN_ON(IS_ERR(object->engine));
 }
 
 int
diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/fb/ramgf100.c b/drivers/gpu/drm/nouveau/nvkm/subdev/fb/ramgf100.c
index c63975907c90..4a9bd4f1cb93 100644
--- a/drivers/gpu/drm/nouveau/nvkm/subdev/fb/ramgf100.c
+++ b/drivers/gpu/drm/nouveau/nvkm/subdev/fb/ramgf100.c
@@ -638,7 +638,6 @@ gf100_ram_ctor(const struct nvkm_ram_func *func, struct nvkm_fb *fb,
                         return ret;
         }
 
-        ram->ranks = (nvkm_rd32(device, 0x10f200) & 0x00000004) ? 2 : 1;
         return 0;
 }
 
diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/therm/base.c b/drivers/gpu/drm/nouveau/nvkm/subdev/therm/base.c
index df949fa7d05d..be691a7b972f 100644
--- a/drivers/gpu/drm/nouveau/nvkm/subdev/therm/base.c
+++ b/drivers/gpu/drm/nouveau/nvkm/subdev/therm/base.c
@@ -146,7 +146,7 @@ nvkm_therm_update(struct nvkm_therm *therm, int mode)
                 poll = false;
         }
 
-        if (list_empty(&therm->alarm.head) && poll)
+        if (poll)
                 nvkm_timer_alarm(tmr, 1000000000ULL, &therm->alarm);
         spin_unlock_irqrestore(&therm->lock, flags);
 
diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/therm/fan.c b/drivers/gpu/drm/nouveau/nvkm/subdev/therm/fan.c
index 91198d79393a..e2feccec25f5 100644
--- a/drivers/gpu/drm/nouveau/nvkm/subdev/therm/fan.c
+++ b/drivers/gpu/drm/nouveau/nvkm/subdev/therm/fan.c
@@ -83,7 +83,7 @@ nvkm_fan_update(struct nvkm_fan *fan, bool immediate, int target)
         spin_unlock_irqrestore(&fan->lock, flags);
 
         /* schedule next fan update, if not at target speed already */
-        if (list_empty(&fan->alarm.head) && target != duty) {
+        if (target != duty) {
                 u16 bump_period = fan->bios.bump_period;
                 u16 slow_down_period = fan->bios.slow_down_period;
                 u64 delay;
diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/therm/fantog.c b/drivers/gpu/drm/nouveau/nvkm/subdev/therm/fantog.c
index 59701b7a6597..ff9fbe7950e5 100644
--- a/drivers/gpu/drm/nouveau/nvkm/subdev/therm/fantog.c
+++ b/drivers/gpu/drm/nouveau/nvkm/subdev/therm/fantog.c
@@ -53,7 +53,7 @@ nvkm_fantog_update(struct nvkm_fantog *fan, int percent)
         duty = !nvkm_gpio_get(gpio, 0, DCB_GPIO_FAN, 0xff);
         nvkm_gpio_set(gpio, 0, DCB_GPIO_FAN, 0xff, duty);
 
-        if (list_empty(&fan->alarm.head) && percent != (duty * 100)) {
+        if (percent != (duty * 100)) {
                 u64 next_change = (percent * fan->period_us) / 100;
                 if (!duty)
                         next_change = fan->period_us - next_change;
diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/therm/temp.c b/drivers/gpu/drm/nouveau/nvkm/subdev/therm/temp.c
index b9703c02d8ca..9a79e91fdfdc 100644
--- a/drivers/gpu/drm/nouveau/nvkm/subdev/therm/temp.c
+++ b/drivers/gpu/drm/nouveau/nvkm/subdev/therm/temp.c
@@ -185,7 +185,7 @@ alarm_timer_callback(struct nvkm_alarm *alarm)
         spin_unlock_irqrestore(&therm->sensor.alarm_program_lock, flags);
 
         /* schedule the next poll in one second */
-        if (therm->func->temp_get(therm) >= 0 && list_empty(&alarm->head))
+        if (therm->func->temp_get(therm) >= 0)
                 nvkm_timer_alarm(tmr, 1000000000ULL, alarm);
 }
 
diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/timer/base.c b/drivers/gpu/drm/nouveau/nvkm/subdev/timer/base.c
index 07dc82bfe346..f2a86eae0a0d 100644
--- a/drivers/gpu/drm/nouveau/nvkm/subdev/timer/base.c
+++ b/drivers/gpu/drm/nouveau/nvkm/subdev/timer/base.c
@@ -36,23 +36,29 @@ nvkm_timer_alarm_trigger(struct nvkm_timer *tmr)
         unsigned long flags;
         LIST_HEAD(exec);
 
-        /* move any due alarms off the pending list */
+        /* Process pending alarms. */
         spin_lock_irqsave(&tmr->lock, flags);
         list_for_each_entry_safe(alarm, atemp, &tmr->alarms, head) {
-                if (alarm->timestamp <= nvkm_timer_read(tmr))
-                        list_move_tail(&alarm->head, &exec);
+                /* Have we hit the earliest alarm that hasn't gone off? */
+                if (alarm->timestamp > nvkm_timer_read(tmr)) {
+                        /* Schedule it.  If we didn't race, we're done. */
+                        tmr->func->alarm_init(tmr, alarm->timestamp);
+                        if (alarm->timestamp > nvkm_timer_read(tmr))
+                                break;
+                }
+
+                /* Move to completed list.  We'll drop the lock before
+                 * executing the callback so it can reschedule itself.
+                 */
+                list_move_tail(&alarm->head, &exec);
         }
 
-        /* reschedule interrupt for next alarm time */
-        if (!list_empty(&tmr->alarms)) {
-                alarm = list_first_entry(&tmr->alarms, typeof(*alarm), head);
-                tmr->func->alarm_init(tmr, alarm->timestamp);
-        } else {
+        /* Shut down interrupt if no more pending alarms. */
+        if (list_empty(&tmr->alarms))
                 tmr->func->alarm_fini(tmr);
-        }
         spin_unlock_irqrestore(&tmr->lock, flags);
 
-        /* execute any pending alarm handlers */
+        /* Execute completed callbacks. */
         list_for_each_entry_safe(alarm, atemp, &exec, head) {
                 list_del_init(&alarm->head);
                 alarm->func(alarm);
@@ -65,24 +71,37 @@ nvkm_timer_alarm(struct nvkm_timer *tmr, u32 nsec, struct nvkm_alarm *alarm)
         struct nvkm_alarm *list;
         unsigned long flags;
 
-        alarm->timestamp = nvkm_timer_read(tmr) + nsec;
-
-        /* append new alarm to list, in soonest-alarm-first order */
+        /* Remove alarm from pending list.
+         *
+         * This both protects against the corruption of the list,
+         * and implements alarm rescheduling/cancellation.
+         */
         spin_lock_irqsave(&tmr->lock, flags);
-        if (!nsec) {
-                if (!list_empty(&alarm->head))
-                        list_del(&alarm->head);
-        } else {
+        list_del_init(&alarm->head);
+
+        if (nsec) {
+                /* Insert into pending list, ordered earliest to latest. */
+                alarm->timestamp = nvkm_timer_read(tmr) + nsec;
                 list_for_each_entry(list, &tmr->alarms, head) {
                         if (list->timestamp > alarm->timestamp)
                                 break;
                 }
+
                 list_add_tail(&alarm->head, &list->head);
+
+                /* Update HW if this is now the earliest alarm. */
+                list = list_first_entry(&tmr->alarms, typeof(*list), head);
+                if (list == alarm) {
+                        tmr->func->alarm_init(tmr, alarm->timestamp);
+                        /* This shouldn't happen if callers aren't stupid.
+                         *
+                         * Worst case scenario is that it'll take roughly
+                         * 4 seconds for the next alarm to trigger.
+                         */
+                        WARN_ON(alarm->timestamp <= nvkm_timer_read(tmr));
+                }
         }
         spin_unlock_irqrestore(&tmr->lock, flags);
-
-        /* process pending alarms */
-        nvkm_timer_alarm_trigger(tmr);
 }
 
 void
diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/timer/nv04.c b/drivers/gpu/drm/nouveau/nvkm/subdev/timer/nv04.c
index 7b9ce87f0617..7f48249f41de 100644
--- a/drivers/gpu/drm/nouveau/nvkm/subdev/timer/nv04.c
+++ b/drivers/gpu/drm/nouveau/nvkm/subdev/timer/nv04.c
@@ -76,8 +76,8 @@ nv04_timer_intr(struct nvkm_timer *tmr)
         u32 stat = nvkm_rd32(device, NV04_PTIMER_INTR_0);
 
         if (stat & 0x00000001) {
-                nvkm_timer_alarm_trigger(tmr);
                 nvkm_wr32(device, NV04_PTIMER_INTR_0, 0x00000001);
+                nvkm_timer_alarm_trigger(tmr);
                 stat &= ~0x00000001;
         }