drm/i915: Make mmio flip wait for seqno in the work function

This simplifies the code quite a bit compared to iterating over all
rings during the ring interrupt.

Also, it allows us to drop the mmio_flip spinlock, since the mmio_flip
struct is only accessed in two places. The first is when the flip is
queued and the other when the mmio writes are done. Since a flip cannot
be queued while there is a pending flip, the two paths shouldn't ever
run in parallel. We might need to revisit that if support for replacing
flips is implemented though.

v2: Don't hold dev->struct_mutext while waiting (Chris)

v3: Make the wait uninterruptable (Chris)

Signed-off-by: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
This commit is contained in:
Ander Conselvan de Oliveira 2014-11-06 11:03:40 +02:00 committed by Daniel Vetter
parent 16e9a21f33
commit 536f5b5e86
3 changed files with 14 additions and 92 deletions

View File

@ -979,9 +979,6 @@ static void notify_ring(struct drm_device *dev,
trace_i915_gem_request_complete(ring);
if (drm_core_check_feature(dev, DRIVER_MODESET))
intel_notify_mmio_flip(ring);
wake_up_all(&ring->irq_queue);
i915_queue_hangcheck(dev);
}

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@ -9417,75 +9417,26 @@ static void intel_do_mmio_flip(struct intel_crtc *intel_crtc)
if (atomic_update)
intel_pipe_update_end(intel_crtc, start_vbl_count);
spin_lock_irq(&dev_priv->mmio_flip_lock);
intel_crtc->mmio_flip.status = INTEL_MMIO_FLIP_IDLE;
spin_unlock_irq(&dev_priv->mmio_flip_lock);
}
static void intel_mmio_flip_work_func(struct work_struct *work)
{
struct intel_crtc *intel_crtc =
container_of(work, struct intel_crtc, mmio_flip.work);
struct intel_engine_cs *ring;
uint32_t seqno;
seqno = intel_crtc->mmio_flip.seqno;
ring = intel_crtc->mmio_flip.ring;
if (seqno)
WARN_ON(__i915_wait_seqno(ring, seqno,
intel_crtc->reset_counter,
false, NULL, NULL) != 0);
intel_do_mmio_flip(intel_crtc);
}
static int intel_postpone_flip(struct drm_i915_gem_object *obj)
{
struct intel_engine_cs *ring;
int ret;
lockdep_assert_held(&obj->base.dev->struct_mutex);
if (!obj->last_write_seqno)
return 0;
ring = obj->ring;
if (i915_seqno_passed(ring->get_seqno(ring, true),
obj->last_write_seqno))
return 0;
ret = i915_gem_check_olr(ring, obj->last_write_seqno);
if (ret)
return ret;
if (WARN_ON(!ring->irq_get(ring)))
return 0;
return 1;
}
void intel_notify_mmio_flip(struct intel_engine_cs *ring)
{
struct drm_i915_private *dev_priv = to_i915(ring->dev);
struct intel_crtc *intel_crtc;
unsigned long irq_flags;
u32 seqno;
seqno = ring->get_seqno(ring, false);
spin_lock_irqsave(&dev_priv->mmio_flip_lock, irq_flags);
for_each_intel_crtc(ring->dev, intel_crtc) {
struct intel_mmio_flip *mmio_flip;
mmio_flip = &intel_crtc->mmio_flip;
if (mmio_flip->status != INTEL_MMIO_FLIP_WAIT_RING)
continue;
if (ring->id != mmio_flip->ring_id)
continue;
if (i915_seqno_passed(seqno, mmio_flip->seqno)) {
schedule_work(&intel_crtc->mmio_flip.work);
mmio_flip->status = INTEL_MMIO_FLIP_WORK_SCHEDULED;
ring->irq_put(ring);
}
}
spin_unlock_irqrestore(&dev_priv->mmio_flip_lock, irq_flags);
}
static int intel_queue_mmio_flip(struct drm_device *dev,
struct drm_crtc *crtc,
struct drm_framebuffer *fb,
@ -9493,32 +9444,13 @@ static int intel_queue_mmio_flip(struct drm_device *dev,
struct intel_engine_cs *ring,
uint32_t flags)
{
struct drm_i915_private *dev_priv = dev->dev_private;
struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
int ret;
if (WARN_ON(intel_crtc->mmio_flip.status != INTEL_MMIO_FLIP_IDLE))
return -EBUSY;
ret = intel_postpone_flip(obj);
if (ret < 0)
return ret;
if (ret == 0) {
intel_do_mmio_flip(intel_crtc);
return 0;
}
spin_lock_irq(&dev_priv->mmio_flip_lock);
intel_crtc->mmio_flip.status = INTEL_MMIO_FLIP_WAIT_RING;
intel_crtc->mmio_flip.seqno = obj->last_write_seqno;
intel_crtc->mmio_flip.ring_id = obj->ring->id;
spin_unlock_irq(&dev_priv->mmio_flip_lock);
intel_crtc->mmio_flip.ring = obj->ring;
schedule_work(&intel_crtc->mmio_flip.work);
/*
* Double check to catch cases where irq fired before
* mmio flip data was ready
*/
intel_notify_mmio_flip(obj->ring);
return 0;
}

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@ -399,16 +399,9 @@ struct intel_pipe_wm {
bool sprites_scaled;
};
enum intel_mmio_flip_status {
INTEL_MMIO_FLIP_IDLE = 0,
INTEL_MMIO_FLIP_WAIT_RING,
INTEL_MMIO_FLIP_WORK_SCHEDULED,
};
struct intel_mmio_flip {
u32 seqno;
u32 ring_id;
enum intel_mmio_flip_status status;
struct intel_engine_cs *ring;
struct work_struct work;
};