drm/i915: Clarify event_lock locking, process context
It's good practice to use the more specific versions for irq save
spinlocks both as executable documentation and to enforce saner
design. The _irqsave version really should only be used if the calling
context is unknown and there's a good reason to call a function from
all kinds of places.
This is the first step whice replaces all occurances of _irqsave in
process context with the simpler irq disable/enable variants. We don't
have any funky spinlock nesting going on, especially since the
event_lock is the outermost of the irq/vblank related spinlocks.
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 365e04c..624d9bf 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -2711,16 +2711,15 @@
struct drm_device *dev = crtc->dev;
struct drm_i915_private *dev_priv = dev->dev_private;
struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
- unsigned long flags;
bool pending;
if (i915_reset_in_progress(&dev_priv->gpu_error) ||
intel_crtc->reset_counter != atomic_read(&dev_priv->gpu_error.reset_counter))
return false;
- spin_lock_irqsave(&dev->event_lock, flags);
+ spin_lock_irq(&dev->event_lock);
pending = to_intel_crtc(crtc)->unpin_work != NULL;
- spin_unlock_irqrestore(&dev->event_lock, flags);
+ spin_unlock_irq(&dev->event_lock);
return pending;
}
@@ -3431,14 +3430,13 @@
!intel_crtc_has_pending_flip(crtc),
60*HZ) == 0)) {
struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
- unsigned long flags;
- spin_lock_irqsave(&dev->event_lock, flags);
+ spin_lock_irq(&dev->event_lock);
if (intel_crtc->unpin_work) {
WARN_ONCE(1, "Removing stuck page flip\n");
page_flip_completed(intel_crtc);
}
- spin_unlock_irqrestore(&dev->event_lock, flags);
+ spin_unlock_irq(&dev->event_lock);
}
if (crtc->primary->fb) {
@@ -9280,12 +9278,11 @@
struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
struct drm_device *dev = crtc->dev;
struct intel_unpin_work *work;
- unsigned long flags;
- spin_lock_irqsave(&dev->event_lock, flags);
+ spin_lock_irq(&dev->event_lock);
work = intel_crtc->unpin_work;
intel_crtc->unpin_work = NULL;
- spin_unlock_irqrestore(&dev->event_lock, flags);
+ spin_unlock_irq(&dev->event_lock);
if (work) {
cancel_work_sync(&work->work);
@@ -9896,7 +9893,6 @@
enum pipe pipe = intel_crtc->pipe;
struct intel_unpin_work *work;
struct intel_engine_cs *ring;
- unsigned long flags;
int ret;
//trigger software GT busyness calculation
@@ -9940,7 +9936,7 @@
goto free_work;
/* We borrow the event spin lock for protecting unpin_work */
- spin_lock_irqsave(&dev->event_lock, flags);
+ spin_lock_irq(&dev->event_lock);
if (intel_crtc->unpin_work) {
/* Before declaring the flip queue wedged, check if
* the hardware completed the operation behind our backs.
@@ -9950,7 +9946,7 @@
page_flip_completed(intel_crtc);
} else {
DRM_DEBUG_DRIVER("flip queue: crtc already busy\n");
- spin_unlock_irqrestore(&dev->event_lock, flags);
+ spin_unlock_irq(&dev->event_lock);
drm_crtc_vblank_put(crtc);
kfree(work);
@@ -9958,7 +9954,7 @@
}
}
intel_crtc->unpin_work = work;
- spin_unlock_irqrestore(&dev->event_lock, flags);
+ spin_unlock_irq(&dev->event_lock);
if (atomic_read(&intel_crtc->unpin_work_count) >= 2)
flush_workqueue(dev_priv->wq);
@@ -10045,9 +10041,9 @@
mutex_unlock(&dev->struct_mutex);
cleanup:
- spin_lock_irqsave(&dev->event_lock, flags);
+ spin_lock_irq(&dev->event_lock);
intel_crtc->unpin_work = NULL;
- spin_unlock_irqrestore(&dev->event_lock, flags);
+ spin_unlock_irq(&dev->event_lock);
drm_crtc_vblank_put(crtc);
free_work:
@@ -10058,9 +10054,9 @@
intel_crtc_wait_for_pending_flips(crtc);
ret = intel_pipe_set_base(crtc, crtc->x, crtc->y, fb);
if (ret == 0 && event) {
- spin_lock_irqsave(&dev->event_lock, flags);
+ spin_lock_irq(&dev->event_lock);
drm_send_vblank_event(dev, pipe, event);
- spin_unlock_irqrestore(&dev->event_lock, flags);
+ spin_unlock_irq(&dev->event_lock);
}
}
return ret;
@@ -13769,9 +13765,8 @@
for_each_intel_crtc(dev, crtc) {
struct intel_unpin_work *work;
- unsigned long irqflags;
- spin_lock_irqsave(&dev->event_lock, irqflags);
+ spin_lock_irq(&dev->event_lock);
work = crtc->unpin_work;
@@ -13781,6 +13776,6 @@
work->event = NULL;
}
- spin_unlock_irqrestore(&dev->event_lock, irqflags);
+ spin_unlock_irq(&dev->event_lock);
}
}