For measuring duration we want to avoid that our start/end timestamps
jump, so use monotonic instead of real time for that.
Signed-off-by: Imre Deak <imre.deak at intel.com>
---
drivers/gpu/drm/drm_irq.c | 18 ++++++++++++------
1 file changed, 12 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c
index 89b830d..7dc203d 100644
--- a/drivers/gpu/drm/drm_irq.c
+++ b/drivers/gpu/drm/drm_irq.c
@@ -576,7 +576,8 @@ int drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev, int crtc,
unsigned flags,
struct drm_crtc *refcrtc)
{
- struct timeval stime, raw_time;
+ ktime_t stime, etime, mono_time_offset;
+ struct timeval tv_etime;
struct drm_display_mode *mode;
int vbl_status, vtotal, vdisplay;
int vpos, hpos, i;
@@ -625,13 +626,14 @@ int drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev, int crtc,
preempt_disable();
/* Get system timestamp before query. */
- do_gettimeofday(&stime);
+ stime = ktime_get();
/* Get vertical and horizontal scanout pos. vpos, hpos. */
vbl_status = dev->driver->get_scanout_position(dev, crtc, &vpos, &hpos);
/* Get system timestamp after query. */
- do_gettimeofday(&raw_time);
+ etime = ktime_get();
+ mono_time_offset = ktime_get_monotonic_offset();
preempt_enable();
@@ -642,7 +644,7 @@ int drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev, int crtc,
return -EIO;
}
- duration_ns = timeval_to_ns(&raw_time) - timeval_to_ns(&stime);
+ duration_ns = ktime_to_ns(etime) - ktime_to_ns(stime);
/* Accept result with < max_error nsecs timing uncertainty. */
if (duration_ns <= (s64) *max_error)
@@ -689,14 +691,18 @@ int drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev, int crtc,
vbl_status |= 0x8;
}
+ etime = ktime_sub(etime, mono_time_offset);
+ /* save this only for debugging purposes */
+ tv_etime = ktime_to_timeval(etime);
/* Subtract time delta from raw timestamp to get final
* vblank_time timestamp for end of vblank.
*/
- *vblank_time = ns_to_timeval(timeval_to_ns(&raw_time) - delta_ns);
+ etime = ktime_sub_ns(etime, delta_ns);
+ *vblank_time = ktime_to_timeval(etime);
DRM_DEBUG("crtc %d : v %d p(%d,%d)@ %ld.%ld -> %ld.%ld [e %d us, %d rep]\n",
crtc, (int)vbl_status, hpos, vpos,
- (long)raw_time.tv_sec, (long)raw_time.tv_usec,
+ (long)tv_etime.tv_sec, (long)tv_etime.tv_usec,
(long)vblank_time->tv_sec, (long)vblank_time->tv_usec,
(int)duration_ns/1000, i);
--
1.7.9.5
