[PATCH 1/2] drm/udl: make page flips asynchronous.
Haixia Shi
hshi at chromium.org
Wed Mar 4 18:26:23 PST 2015
This also limits the maximum frequency of page flips by the vrefresh rate.
Signed-off-by: Haixia Shi <hshi at chromium.org>
Reviewed-by: Stéphane Marchesin <marcheu at chromium.org>
Tested-by: Haixia Shi <hshi at chromium.org>
---
drivers/gpu/drm/udl/udl_drv.h | 3 +
drivers/gpu/drm/udl/udl_modeset.c | 129 ++++++++++++++++++++++++++++++++++----
2 files changed, 119 insertions(+), 13 deletions(-)
diff --git a/drivers/gpu/drm/udl/udl_drv.h b/drivers/gpu/drm/udl/udl_drv.h
index 80adbac..b1e9fae 100644
--- a/drivers/gpu/drm/udl/udl_drv.h
+++ b/drivers/gpu/drm/udl/udl_drv.h
@@ -47,6 +47,7 @@ struct urb_list {
};
struct udl_fbdev;
+struct udl_flip_queue;
struct udl_device {
struct device *dev;
@@ -65,6 +66,8 @@ struct udl_device {
atomic_t bytes_identical; /* saved effort with backbuffer comparison */
atomic_t bytes_sent; /* to usb, after compression including overhead */
atomic_t cpu_kcycles_used; /* transpired during pixel processing */
+
+ struct udl_flip_queue *flip_queue;
};
struct udl_gem_object {
diff --git a/drivers/gpu/drm/udl/udl_modeset.c b/drivers/gpu/drm/udl/udl_modeset.c
index 677190a6..f3804b4 100644
--- a/drivers/gpu/drm/udl/udl_modeset.c
+++ b/drivers/gpu/drm/udl/udl_modeset.c
@@ -303,6 +303,16 @@ udl_pipe_set_base(struct drm_crtc *crtc, int x, int y,
}
#endif
+struct udl_flip_queue {
+ struct mutex lock;
+ struct workqueue_struct *wq;
+ struct delayed_work work;
+ struct drm_crtc *crtc;
+ struct drm_pending_vblank_event *event;
+ u64 flip_time; /* in jiffies */
+ u64 vblank_interval; /* in jiffies */
+};
+
static int udl_crtc_mode_set(struct drm_crtc *crtc,
struct drm_display_mode *mode,
struct drm_display_mode *adjusted_mode,
@@ -313,6 +323,7 @@ static int udl_crtc_mode_set(struct drm_crtc *crtc,
struct drm_device *dev = crtc->dev;
struct udl_framebuffer *ufb = to_udl_fb(crtc->primary->fb);
struct udl_device *udl = dev->dev_private;
+ struct udl_flip_queue *flip_queue = udl->flip_queue;
char *buf;
char *wrptr;
int color_depth = 0;
@@ -347,6 +358,13 @@ static int udl_crtc_mode_set(struct drm_crtc *crtc,
ufb->active_16 = true;
udl->mode_buf_len = wrptr - buf;
+ /* update flip queue vblank interval */
+ if (flip_queue) {
+ mutex_lock(&flip_queue->lock);
+ flip_queue->vblank_interval = HZ / mode->vrefresh;
+ mutex_unlock(&flip_queue->lock);
+ }
+
/* damage all of it */
udl_handle_damage(ufb, 0, 0, ufb->base.width, ufb->base.height);
return 0;
@@ -364,29 +382,82 @@ static void udl_crtc_destroy(struct drm_crtc *crtc)
kfree(crtc);
}
+static void udl_sched_page_flip(struct work_struct *work)
+{
+ struct udl_flip_queue *flip_queue =
+ container_of(container_of(work, struct delayed_work, work),
+ struct udl_flip_queue, work);
+ struct drm_crtc *crtc;
+ struct drm_device *dev;
+ struct drm_pending_vblank_event *event;
+ struct drm_framebuffer *fb;
+
+ mutex_lock(&flip_queue->lock);
+ crtc = flip_queue->crtc;
+ dev = crtc->dev;
+ event = flip_queue->event;
+ fb = crtc->primary->fb;
+ flip_queue->event = NULL;
+ mutex_unlock(&flip_queue->lock);
+
+ if (fb)
+ udl_handle_damage(to_udl_fb(fb), 0, 0, fb->width, fb->height);
+ if (event) {
+ unsigned long flags;
+ spin_lock_irqsave(&dev->event_lock, flags);
+ drm_send_vblank_event(dev, 0, event);
+ spin_unlock_irqrestore(&dev->event_lock, flags);
+ }
+}
+
static int udl_crtc_page_flip(struct drm_crtc *crtc,
struct drm_framebuffer *fb,
struct drm_pending_vblank_event *event,
uint32_t page_flip_flags)
{
- struct udl_framebuffer *ufb = to_udl_fb(fb);
struct drm_device *dev = crtc->dev;
- unsigned long flags;
+ struct udl_device *udl = dev->dev_private;
+ struct udl_flip_queue *flip_queue = udl->flip_queue;
- struct drm_framebuffer *old_fb = crtc->primary->fb;
- if (old_fb) {
- struct udl_framebuffer *uold_fb = to_udl_fb(old_fb);
- uold_fb->active_16 = false;
+ if (!flip_queue || !flip_queue->wq) {
+ DRM_ERROR("Uninitialized page flip queue\n");
+ return -ENOMEM;
}
- ufb->active_16 = true;
- udl_handle_damage(ufb, 0, 0, fb->width, fb->height);
+ mutex_lock(&flip_queue->lock);
+
+ flip_queue->crtc = crtc;
+ if (fb) {
+ struct drm_framebuffer *old_fb;
+ struct udl_framebuffer *ufb;
+ ufb = to_udl_fb(fb);
+ old_fb = crtc->primary->fb;
+ if (old_fb) {
+ struct udl_framebuffer *uold_fb = to_udl_fb(old_fb);
+ uold_fb->active_16 = false;
+ }
+ ufb->active_16 = true;
+ crtc->primary->fb = fb;
+ }
+ if (event) {
+ if (flip_queue->event) {
+ unsigned long flags;
+ spin_lock_irqsave(&dev->event_lock, flags);
+ drm_send_vblank_event(dev, 0, flip_queue->event);
+ spin_unlock_irqrestore(&dev->event_lock, flags);
+ }
+ flip_queue->event = event;
+ }
+ if (!delayed_work_pending(&flip_queue->work)) {
+ u64 now = jiffies;
+ u64 next_flip =
+ flip_queue->flip_time + flip_queue->vblank_interval;
+ flip_queue->flip_time = (next_flip < now) ? now : next_flip;
+ queue_delayed_work(flip_queue->wq, &flip_queue->work,
+ flip_queue->flip_time - now);
+ }
- spin_lock_irqsave(&dev->event_lock, flags);
- if (event)
- drm_send_vblank_event(dev, 0, event);
- spin_unlock_irqrestore(&dev->event_lock, flags);
- crtc->primary->fb = fb;
+ mutex_unlock(&flip_queue->lock);
return 0;
}
@@ -429,6 +500,35 @@ static int udl_crtc_init(struct drm_device *dev)
return 0;
}
+static void udl_flip_workqueue_init(struct drm_device *dev)
+{
+ struct udl_device *udl = dev->dev_private;
+ struct udl_flip_queue *flip_queue =
+ kzalloc(sizeof(struct udl_flip_queue), GFP_KERNEL);
+ BUG_ON(!flip_queue);
+ mutex_init(&flip_queue->lock);
+ flip_queue->wq = create_singlethread_workqueue("flip");
+ BUG_ON(!flip_queue->wq);
+ INIT_DELAYED_WORK(&flip_queue->work, udl_sched_page_flip);
+ flip_queue->flip_time = jiffies;
+ flip_queue->vblank_interval = HZ / 60;
+ udl->flip_queue = flip_queue;
+}
+
+static void udl_flip_workqueue_cleanup(struct drm_device *dev)
+{
+ struct udl_device *udl = dev->dev_private;
+ struct udl_flip_queue *flip_queue = udl->flip_queue;
+ if (!flip_queue)
+ return;
+ if (flip_queue->wq) {
+ flush_workqueue(flip_queue->wq);
+ destroy_workqueue(flip_queue->wq);
+ }
+ mutex_destroy(&flip_queue->lock);
+ kfree(flip_queue);
+}
+
static const struct drm_mode_config_funcs udl_mode_funcs = {
.fb_create = udl_fb_user_fb_create,
.output_poll_changed = NULL,
@@ -458,10 +558,13 @@ int udl_modeset_init(struct drm_device *dev)
udl_connector_init(dev, encoder);
+ udl_flip_workqueue_init(dev);
+
return 0;
}
void udl_modeset_cleanup(struct drm_device *dev)
{
+ udl_flip_workqueue_cleanup(dev);
drm_mode_config_cleanup(dev);
}
--
2.2.0.rc0.207.ga3a616c
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