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drm/virtio: send vblank event when pageflip timeout #65

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drm/virtio: send vblank event when pageflip timeout #65

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a9de7c9
drm/virtio: send vblank event when pageflip timeout
bosheng1 Jun 10, 2025
23686c1
drm/virtio: delay disable vq when having unprocessed pageflip event
bosheng1 Jun 17, 2025
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7 changes: 6 additions & 1 deletion drivers/gpu/drm/virtio/virtgpu_display.c
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Original file line number Diff line number Diff line change
Expand Up @@ -61,6 +61,7 @@ static int virtio_irq_enable_vblank(struct drm_crtc *crtc)
do {
virtio_gpu_vblank_poll_arm(vgdev->vblank[output->index].vblank.vq);
} while (!virtqueue_enable_cb(vgdev->vblank[output->index].vblank.vq));
vgdev->vblank[output->index].enabled = true;
return 0;
}

Expand All @@ -71,7 +72,11 @@ static void virtio_irq_disable_vblank(struct drm_crtc *crtc)
vgdev = dev->dev_private;
struct virtio_gpu_output *output = drm_crtc_to_virtio_gpu_output(crtc);

virtqueue_disable_cb(vgdev->vblank[output->index].vblank.vq);
if (vgdev->cache_event[output->index]) {
printk("bosheng pending event in disable vblank\n");
virtqueue_disable_cb(vgdev->vblank[output->index].vblank.vq);
vgdev->vblank[output->index].enabled = false;
}
}

static const struct drm_crtc_funcs virtio_gpu_crtc_funcs = {
Expand Down
2 changes: 2 additions & 0 deletions drivers/gpu/drm/virtio/virtgpu_drv.h
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Original file line number Diff line number Diff line change
Expand Up @@ -255,6 +255,8 @@ struct virtio_gpu_drv_cap_cache {
struct virtio_gpu_vblank {
struct virtio_gpu_queue vblank;
uint32_t buf[4];
uint32_t idle_vblank_count;
bool enabled;
};

static inline bool drm_vblank_passed(u64 seq, u64 ref)
Expand Down
24 changes: 20 additions & 4 deletions drivers/gpu/drm/virtio/virtgpu_vq.c
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Original file line number Diff line number Diff line change
Expand Up @@ -93,6 +93,7 @@ void virtio_gpu_vblank_poll_arm(struct virtqueue *vq)
spin_unlock_irqrestore(&vgdev->vblank[target].vblank.qlock, irqflags);
}

#define PAGEFLIP_RESET 10
void virtio_gpu_vblank_ack(struct virtqueue *vq)
{
struct drm_device *dev = vq->vdev->priv;
Expand All @@ -101,6 +102,7 @@ void virtio_gpu_vblank_ack(struct virtqueue *vq)
unsigned int len;
unsigned int *ret_value;
unsigned target = 0;
bool timeout = false;

while((target < vgdev->num_vblankq) && (vgdev->vblank[target].vblank.vq != vq)) {
target++;
Expand All @@ -114,6 +116,10 @@ void virtio_gpu_vblank_ack(struct virtqueue *vq)
drm_handle_vblank(dev, target);

if (*ret_value != 0) {
if (atomic64_read(&vgdev->flip_sequence[target]) == *ret_value)
vgdev->vblank[target].idle_vblank_count++;
else
vgdev->vblank[target].idle_vblank_count = 0;
atomic64_set(&vgdev->flip_sequence[target], *ret_value);
}

Expand All @@ -123,10 +129,20 @@ void virtio_gpu_vblank_ack(struct virtqueue *vq)
return;

struct drm_pending_vblank_event *e = xchg(&vgdev->cache_event[target], NULL);
if (!e)
if (!e) {
spin_lock_irqsave(&dev->vblank_time_lock, irqflags);
if (!dev->vblank[target].enabled && vgdev->vblank[target].enabled) {
virtqueue_disable_cb(vgdev->vblank[target].vblank.vq);
vgdev->vblank[target].enabled = false;
}
spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags);
return;

if (drm_vblank_passed(atomic64_read(&vgdev->flip_sequence[target]),
}
if (vgdev->vblank[target].idle_vblank_count >= PAGEFLIP_RESET) {
vgdev->vblank[target].idle_vblank_count = 0;
timeout = true;
}
if (timeout || drm_vblank_passed(atomic64_read(&vgdev->flip_sequence[target]),
e->sequence)) {
spin_lock_irqsave(&dev->event_lock, irqflags);
drm_crtc_send_vblank_event(&vgdev->outputs[target].crtc, e);
Expand Down Expand Up @@ -559,7 +575,7 @@ void virtio_gpu_vblankq_notify(struct virtio_gpu_device *vgdev)

for(i=0; i < vgdev->num_vblankq; i++) {
spin_lock_irqsave(&vgdev->vblank[i].vblank.qlock, irqflags);

vgdev->vblank[i].idle_vblank_count = 0;
size = virtqueue_get_vring_size(vgdev->vblank[i].vblank.vq);
if (size > ARRAY_SIZE(vgdev->vblank[i].buf))
size = ARRAY_SIZE(vgdev->vblank[i].buf);
Expand Down