diff options
| author | Ville Syrjälä <ville.syrjala@linux.intel.com> | 2015-09-14 22:43:44 +0300 |
|---|---|---|
| committer | Daniel Vetter <daniel.vetter@ffwll.ch> | 2015-09-24 20:14:21 +0200 |
| commit | 3bb403bf421b5b00366a9041a7edc0a1f6494f5e (patch) | |
| tree | d280555ef17c89c2a1e952d03749d230547598c3 /drivers/gpu/drm/amd/amdgpu/amdgpu_display.c | |
| parent | eba1f35dfe145247c7eb690c7c32740fde8ec699 (diff) | |
| download | lwn-3bb403bf421b5b00366a9041a7edc0a1f6494f5e.tar.gz lwn-3bb403bf421b5b00366a9041a7edc0a1f6494f5e.zip | |
drm: Stop using linedur_ns and pixeldur_ns for vblank timestamps
linedur_ns, and especially pixeldur_ns are becoming rather inaccurate
to be used for the vblank timestamp correction. With 4k@60 the pixel
duration is already below 2ns, so the amount of error due to the
truncation to nanoseconds is introducing quite a bit of error.
We can avoid such problems if we instead calculate the timestamp
delta_ns directly from the dislay timings, avoiding the use of
these intermediate truncated values.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
[danvet: Squash in fixup from Thierry Reding for amdgpu.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Diffstat (limited to 'drivers/gpu/drm/amd/amdgpu/amdgpu_display.c')
| -rw-r--r-- | drivers/gpu/drm/amd/amdgpu/amdgpu_display.c | 11 |
1 files changed, 6 insertions, 5 deletions
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c index e3d70772b531..9b34a3410c32 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c @@ -745,7 +745,8 @@ bool amdgpu_crtc_scaling_mode_fixup(struct drm_crtc *crtc, * */ int amdgpu_get_crtc_scanoutpos(struct drm_device *dev, int crtc, unsigned int flags, - int *vpos, int *hpos, ktime_t *stime, ktime_t *etime) + int *vpos, int *hpos, ktime_t *stime, ktime_t *etime, + const struct drm_display_mode *mode) { u32 vbl = 0, position = 0; int vbl_start, vbl_end, vtotal, ret = 0; @@ -781,7 +782,7 @@ int amdgpu_get_crtc_scanoutpos(struct drm_device *dev, int crtc, unsigned int fl } else { /* No: Fake something reasonable which gives at least ok results. */ - vbl_start = adev->mode_info.crtcs[crtc]->base.hwmode.crtc_vdisplay; + vbl_start = mode->crtc_vdisplay; vbl_end = 0; } @@ -797,7 +798,7 @@ int amdgpu_get_crtc_scanoutpos(struct drm_device *dev, int crtc, unsigned int fl /* Inside "upper part" of vblank area? Apply corrective offset if so: */ if (in_vbl && (*vpos >= vbl_start)) { - vtotal = adev->mode_info.crtcs[crtc]->base.hwmode.crtc_vtotal; + vtotal = mode->crtc_vtotal; *vpos = *vpos - vtotal; } @@ -819,8 +820,8 @@ int amdgpu_get_crtc_scanoutpos(struct drm_device *dev, int crtc, unsigned int fl * We only do this if DRM_CALLED_FROM_VBLIRQ. */ if ((flags & DRM_CALLED_FROM_VBLIRQ) && !in_vbl) { - vbl_start = adev->mode_info.crtcs[crtc]->base.hwmode.crtc_vdisplay; - vtotal = adev->mode_info.crtcs[crtc]->base.hwmode.crtc_vtotal; + vbl_start = mode->crtc_vdisplay; + vtotal = mode->crtc_vtotal; if (vbl_start - *vpos < vtotal / 100) { *vpos -= vtotal; |