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-rw-r--r--linux-core/drmP.h8
-rw-r--r--linux-core/drm_irq.c74
2 files changed, 55 insertions, 27 deletions
diff --git a/linux-core/drmP.h b/linux-core/drmP.h
index 331f3ac5..45a599b4 100644
--- a/linux-core/drmP.h
+++ b/linux-core/drmP.h
@@ -832,6 +832,14 @@ struct drm_device {
/** \name VBLANK IRQ support */
/*@{ */
+ /*
+ * At load time, disabling the vblank interrupt won't be allowed since
+ * old clients may not call the modeset ioctl and therefore misbehave.
+ * Once the modeset ioctl *has* been called though, we can safely
+ * disable them when unused.
+ */
+ int vblank_disable_allowed;
+
wait_queue_head_t *vbl_queue; /**< VBLANK wait queue */
atomic_t *_vblank_count; /**< number of VBLANK interrupts (driver must alloc the right number of counters) */
spinlock_t vbl_lock;
diff --git a/linux-core/drm_irq.c b/linux-core/drm_irq.c
index abedbe73..75e53da9 100644
--- a/linux-core/drm_irq.c
+++ b/linux-core/drm_irq.c
@@ -77,10 +77,16 @@ static void vblank_disable_fn(unsigned long arg)
unsigned long irqflags;
int i;
+ if (!dev->vblank_disable_allowed)
+ return;
+
for (i = 0; i < dev->num_crtcs; i++) {
spin_lock_irqsave(&dev->vbl_lock, irqflags);
if (atomic_read(&dev->vblank_refcount[i]) == 0 &&
dev->vblank_enabled[i]) {
+ DRM_DEBUG("disabling vblank on crtc %d\n", i);
+ dev->last_vblank[i] =
+ dev->driver->get_vblank_counter(dev, i);
dev->driver->disable_vblank(dev, i);
dev->vblank_enabled[i] = 0;
}
@@ -175,6 +181,8 @@ int drm_vblank_init(struct drm_device *dev, int num_crtcs)
atomic_set(&dev->vblank_refcount[i], 0);
}
+ dev->vblank_disable_allowed = 0;
+
return 0;
err:
@@ -344,10 +352,15 @@ EXPORT_SYMBOL(drm_vblank_count);
* (specified by @crtc). Deal with wraparound, if it occurred, and
* update the last read value so we can deal with wraparound on the next
* call if necessary.
+ *
+ * Only necessary when going from off->on, to account for frames we
+ * didn't get an interrupt for.
+ *
+ * Note: caller must hold dev->vbl_lock since this reads & writes
+ * device vblank fields.
*/
void drm_update_vblank_count(struct drm_device *dev, int crtc)
{
- unsigned long irqflags;
u32 cur_vblank, diff;
if (dev->vblank_suspend[crtc])
@@ -361,7 +374,6 @@ void drm_update_vblank_count(struct drm_device *dev, int crtc)
* a long time.
*/
cur_vblank = dev->driver->get_vblank_counter(dev, crtc);
- spin_lock_irqsave(&dev->vbl_lock, irqflags);
if (cur_vblank < dev->last_vblank[crtc]) {
if (cur_vblank == dev->last_vblank[crtc] - 1) {
diff = 0;
@@ -377,11 +389,12 @@ void drm_update_vblank_count(struct drm_device *dev, int crtc)
diff = cur_vblank - dev->last_vblank[crtc];
}
dev->last_vblank[crtc] = cur_vblank;
- spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
+
+ DRM_DEBUG("enabling vblank interrupts on crtc %d, missed %d\n",
+ crtc, diff);
atomic_add(diff, &dev->_vblank_count[crtc]);
}
-EXPORT_SYMBOL(drm_update_vblank_count);
/**
* drm_vblank_get - get a reference count on vblank events
@@ -389,9 +402,7 @@ EXPORT_SYMBOL(drm_update_vblank_count);
* @crtc: which CRTC to own
*
* Acquire a reference count on vblank events to avoid having them disabled
- * while in use. Note callers will probably want to update the master counter
- * using drm_update_vblank_count() above before calling this routine so that
- * wakeups occur on the right vblank event.
+ * while in use.
*
* RETURNS
* Zero on success, nonzero on failure.
@@ -408,8 +419,10 @@ int drm_vblank_get(struct drm_device *dev, int crtc)
ret = dev->driver->enable_vblank(dev, crtc);
if (ret)
atomic_dec(&dev->vblank_refcount[crtc]);
- else
+ else {
dev->vblank_enabled[crtc] = 1;
+ drm_update_vblank_count(dev, crtc);
+ }
}
spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
@@ -439,11 +452,18 @@ EXPORT_SYMBOL(drm_vblank_put);
*
* Applications should call the %_DRM_PRE_MODESET and %_DRM_POST_MODESET
* ioctls around modesetting so that any lost vblank events are accounted for.
+ *
+ * Generally the counter will reset across mode sets. If interrupts are
+ * enabled around this call, we don't have to do anything since the counter
+ * will have already been incremented. If interrupts are off though, we need
+ * to make sure we account for the lost events at %_DRM_POST_MODESET time.
*/
int drm_modeset_ctl(struct drm_device *dev, void *data,
struct drm_file *file_priv)
{
struct drm_modeset_ctl *modeset = data;
+ unsigned long irqflags;
+ u32 new, diff;
int crtc, ret = 0;
crtc = modeset->crtc;
@@ -454,27 +474,28 @@ int drm_modeset_ctl(struct drm_device *dev, void *data,
switch (modeset->cmd) {
case _DRM_PRE_MODESET:
- dev->vblank_premodeset[crtc] =
- dev->driver->get_vblank_counter(dev, crtc);
- dev->vblank_suspend[crtc] = 1;
+ spin_lock_irqsave(&dev->vbl_lock, irqflags);
+ dev->vblank_disable_allowed = 1;
+ if (!dev->vblank_enabled[crtc]) {
+ dev->vblank_premodeset[crtc] =
+ dev->driver->get_vblank_counter(dev, crtc);
+ dev->vblank_suspend[crtc] = 1;
+ }
+ spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
break;
case _DRM_POST_MODESET:
- if (dev->vblank_suspend[crtc]) {
- u32 new = dev->driver->get_vblank_counter(dev, crtc);
-
- /* Compensate for spurious wraparound */
- if (new < dev->vblank_premodeset[crtc]) {
- atomic_sub(dev->max_vblank_count + new -
- dev->vblank_premodeset[crtc],
- &dev->_vblank_count[crtc]);
- DRM_DEBUG("vblank_premodeset[%d]=0x%x, new=0x%x"
- " => _vblank_count[%d]-=0x%x\n", crtc,
- dev->vblank_premodeset[crtc], new,
- crtc, dev->max_vblank_count + new -
- dev->vblank_premodeset[crtc]);
- }
+ spin_lock_irqsave(&dev->vbl_lock, irqflags);
+ dev->vblank_disable_allowed = 1;
+ new = dev->driver->get_vblank_counter(dev, crtc);
+ if (dev->vblank_suspend[crtc] && !dev->vblank_enabled[crtc]) {
+ if (new > dev->vblank_premodeset[crtc])
+ diff = dev->vblank_premodeset[crtc] - new;
+ else
+ diff = new;
+ atomic_add(diff, &dev->_vblank_count[crtc]);
}
dev->vblank_suspend[crtc] = 0;
+ spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
break;
default:
ret = -EINVAL;
@@ -528,7 +549,6 @@ int drm_wait_vblank(struct drm_device *dev, void *data,
if (crtc >= dev->num_crtcs)
return -EINVAL;
- drm_update_vblank_count(dev, crtc);
seq = drm_vblank_count(dev, crtc);
switch (vblwait->request.type & _DRM_VBLANK_TYPES_MASK) {
@@ -680,7 +700,7 @@ static void drm_vbl_send_signals(struct drm_device * dev, int crtc)
*/
void drm_handle_vblank(struct drm_device *dev, int crtc)
{
- drm_update_vblank_count(dev, crtc);
+ atomic_inc(&dev->_vblank_count[crtc]);
DRM_WAKEUP(&dev->vbl_queue[crtc]);
drm_vbl_send_signals(dev, crtc);
}
generated by cgit v1.2.3 (git 2.25.1) at 2025-10-31 01:47:22 +0000