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path: root/drivers/gpu/drm/drm_vblank.c
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Diffstat (limited to 'drivers/gpu/drm/drm_vblank.c')
-rw-r--r--drivers/gpu/drm/drm_vblank.c85
1 files changed, 69 insertions, 16 deletions
diff --git a/drivers/gpu/drm/drm_vblank.c b/drivers/gpu/drm/drm_vblank.c
index 603ab105125d..1659b13b178c 100644
--- a/drivers/gpu/drm/drm_vblank.c
+++ b/drivers/gpu/drm/drm_vblank.c
@@ -31,7 +31,6 @@
#include <drm/drm_drv.h>
#include <drm/drm_framebuffer.h>
#include <drm/drm_print.h>
-#include <drm/drm_os_linux.h>
#include <drm/drm_vblank.h>
#include "drm_internal.h"
@@ -107,7 +106,7 @@ static void store_vblank(struct drm_device *dev, unsigned int pipe,
write_seqlock(&vblank->seqlock);
vblank->time = t_vblank;
- vblank->count += vblank_count_inc;
+ atomic64_add(vblank_count_inc, &vblank->count);
write_sequnlock(&vblank->seqlock);
}
@@ -273,7 +272,8 @@ static void drm_update_vblank_count(struct drm_device *dev, unsigned int pipe,
DRM_DEBUG_VBL("updating vblank count on crtc %u:"
" current=%llu, diff=%u, hw=%u hw_last=%u\n",
- pipe, vblank->count, diff, cur_vblank, vblank->last);
+ pipe, atomic64_read(&vblank->count), diff,
+ cur_vblank, vblank->last);
if (diff == 0) {
WARN_ON_ONCE(cur_vblank != vblank->last);
@@ -295,11 +295,23 @@ static void drm_update_vblank_count(struct drm_device *dev, unsigned int pipe,
static u64 drm_vblank_count(struct drm_device *dev, unsigned int pipe)
{
struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
+ u64 count;
if (WARN_ON(pipe >= dev->num_crtcs))
return 0;
- return vblank->count;
+ count = atomic64_read(&vblank->count);
+
+ /*
+ * This read barrier corresponds to the implicit write barrier of the
+ * write seqlock in store_vblank(). Note that this is the only place
+ * where we need an explicit barrier, since all other access goes
+ * through drm_vblank_count_and_time(), which already has the required
+ * read barrier curtesy of the read seqlock.
+ */
+ smp_rmb();
+
+ return count;
}
/**
@@ -320,7 +332,7 @@ u64 drm_crtc_accurate_vblank_count(struct drm_crtc *crtc)
u64 vblank;
unsigned long flags;
- WARN_ONCE(drm_debug & DRM_UT_VBL && !dev->driver->get_vblank_timestamp,
+ WARN_ONCE(drm_debug_enabled(DRM_UT_VBL) && !dev->driver->get_vblank_timestamp,
"This function requires support for accurate vblank timestamps.");
spin_lock_irqsave(&dev->vblank_time_lock, flags);
@@ -694,7 +706,7 @@ bool drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev,
*/
*vblank_time = ktime_sub_ns(etime, delta_ns);
- if ((drm_debug & DRM_UT_VBL) == 0)
+ if (!drm_debug_enabled(DRM_UT_VBL))
return true;
ts_etime = ktime_to_timespec64(etime);
@@ -764,6 +776,14 @@ drm_get_last_vbltimestamp(struct drm_device *dev, unsigned int pipe,
* vblank interrupt (since it only reports the software vblank counter), see
* drm_crtc_accurate_vblank_count() for such use-cases.
*
+ * Note that for a given vblank counter value drm_crtc_handle_vblank()
+ * and drm_crtc_vblank_count() or drm_crtc_vblank_count_and_time()
+ * provide a barrier: Any writes done before calling
+ * drm_crtc_handle_vblank() will be visible to callers of the later
+ * functions, iff the vblank count is the same or a later one.
+ *
+ * See also &drm_vblank_crtc.count.
+ *
* Returns:
* The software vblank counter.
*/
@@ -801,7 +821,7 @@ static u64 drm_vblank_count_and_time(struct drm_device *dev, unsigned int pipe,
do {
seq = read_seqbegin(&vblank->seqlock);
- vblank_count = vblank->count;
+ vblank_count = atomic64_read(&vblank->count);
*vblanktime = vblank->time;
} while (read_seqretry(&vblank->seqlock, seq));
@@ -818,6 +838,14 @@ static u64 drm_vblank_count_and_time(struct drm_device *dev, unsigned int pipe,
* vblank events since the system was booted, including lost events due to
* modesetting activity. Returns corresponding system timestamp of the time
* of the vblank interval that corresponds to the current vblank counter value.
+ *
+ * Note that for a given vblank counter value drm_crtc_handle_vblank()
+ * and drm_crtc_vblank_count() or drm_crtc_vblank_count_and_time()
+ * provide a barrier: Any writes done before calling
+ * drm_crtc_handle_vblank() will be visible to callers of the later
+ * functions, iff the vblank count is the same or a later one.
+ *
+ * See also &drm_vblank_crtc.count.
*/
u64 drm_crtc_vblank_count_and_time(struct drm_crtc *crtc,
ktime_t *vblanktime)
@@ -1324,7 +1352,7 @@ void drm_vblank_restore(struct drm_device *dev, unsigned int pipe)
assert_spin_locked(&dev->vblank_time_lock);
vblank = &dev->vblank[pipe];
- WARN_ONCE((drm_debug & DRM_UT_VBL) && !vblank->framedur_ns,
+ WARN_ONCE(drm_debug_enabled(DRM_UT_VBL) && !vblank->framedur_ns,
"Cannot compute missed vblanks without frame duration\n");
framedur_ns = vblank->framedur_ns;
@@ -1582,7 +1610,7 @@ int drm_wait_vblank_ioctl(struct drm_device *dev, void *data,
unsigned int flags, pipe, high_pipe;
if (!dev->irq_enabled)
- return -EINVAL;
+ return -EOPNOTSUPP;
if (vblwait->request.type & _DRM_VBLANK_SIGNAL)
return -EINVAL;
@@ -1670,12 +1698,28 @@ int drm_wait_vblank_ioctl(struct drm_device *dev, void *data,
}
if (req_seq != seq) {
+ int wait;
+
DRM_DEBUG("waiting on vblank count %llu, crtc %u\n",
req_seq, pipe);
- DRM_WAIT_ON(ret, vblank->queue, 3 * HZ,
- vblank_passed(drm_vblank_count(dev, pipe),
- req_seq) ||
- !READ_ONCE(vblank->enabled));
+ wait = wait_event_interruptible_timeout(vblank->queue,
+ vblank_passed(drm_vblank_count(dev, pipe), req_seq) ||
+ !READ_ONCE(vblank->enabled),
+ msecs_to_jiffies(3000));
+
+ switch (wait) {
+ case 0:
+ /* timeout */
+ ret = -EBUSY;
+ break;
+ case -ERESTARTSYS:
+ /* interrupted by signal */
+ ret = -EINTR;
+ break;
+ default:
+ ret = 0;
+ break;
+ }
}
if (ret != -EINTR) {
@@ -1716,7 +1760,8 @@ static void drm_handle_vblank_events(struct drm_device *dev, unsigned int pipe)
send_vblank_event(dev, e, seq, now);
}
- trace_drm_vblank_event(pipe, seq);
+ trace_drm_vblank_event(pipe, seq, now,
+ dev->driver->get_vblank_timestamp != NULL);
}
/**
@@ -1791,6 +1836,14 @@ EXPORT_SYMBOL(drm_handle_vblank);
*
* This is the native KMS version of drm_handle_vblank().
*
+ * Note that for a given vblank counter value drm_crtc_handle_vblank()
+ * and drm_crtc_vblank_count() or drm_crtc_vblank_count_and_time()
+ * provide a barrier: Any writes done before calling
+ * drm_crtc_handle_vblank() will be visible to callers of the later
+ * functions, iff the vblank count is the same or a later one.
+ *
+ * See also &drm_vblank_crtc.count.
+ *
* Returns:
* True if the event was successfully handled, false on failure.
*/
@@ -1823,7 +1876,7 @@ int drm_crtc_get_sequence_ioctl(struct drm_device *dev, void *data,
return -EOPNOTSUPP;
if (!dev->irq_enabled)
- return -EINVAL;
+ return -EOPNOTSUPP;
crtc = drm_crtc_find(dev, file_priv, get_seq->crtc_id);
if (!crtc)
@@ -1881,7 +1934,7 @@ int drm_crtc_queue_sequence_ioctl(struct drm_device *dev, void *data,
return -EOPNOTSUPP;
if (!dev->irq_enabled)
- return -EINVAL;
+ return -EOPNOTSUPP;
crtc = drm_crtc_find(dev, file_priv, queue_seq->crtc_id);
if (!crtc)
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