From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
Currently intel_crtc_scanline_offset() is careful to always
return a positive offset. That is not actually necessary
as long as we take care of negative values when applying the
offset in __intel_get_crtc_scanline().
This simplifies intel_crtc_scanline_offset(), and makes
the scanline_offfset arithmetic more symmetric between
the forwad (__intel_get_crtc_scanline()) and reverse
(intel_crtc_scanline_to_hw()) directions.
Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
---
drivers/gpu/drm/i915/display/intel_vblank.c | 8 +++-----
1 file changed, 3 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/i915/display/intel_vblank.c b/drivers/gpu/drm/i915/display/intel_vblank.c
index 31fa5867e1a7..b0e95a4c680d 100644
--- a/drivers/gpu/drm/i915/display/intel_vblank.c
+++ b/drivers/gpu/drm/i915/display/intel_vblank.c
@@ -240,7 +240,7 @@ static int __intel_get_crtc_scanline(struct intel_crtc *crtc)
* See update_scanline_offset() for the details on the
* scanline_offset adjustment.
*/
- return (position + crtc->scanline_offset) % vtotal;
+ return (position + vtotal + crtc->scanline_offset) % vtotal;
}
int intel_crtc_scanline_to_hw(struct intel_crtc *crtc, int scanline)
@@ -470,7 +470,6 @@ void intel_wait_for_pipe_scanline_moving(struct intel_crtc *crtc)
static int intel_crtc_scanline_offset(const struct intel_crtc_state *crtc_state)
{
struct drm_i915_private *i915 = to_i915(crtc_state->uapi.crtc->dev);
- const struct drm_display_mode *adjusted_mode = &crtc_state->hw.adjusted_mode;
/*
* The scanline counter increments at the leading edge of hsync.
@@ -482,8 +481,7 @@ static int intel_crtc_scanline_offset(const struct intel_crtc_state *crtc_state)
* last active line), the scanline counter will read vblank_start-1.
*
* On gen2 the scanline counter starts counting from 1 instead
- * of vtotal-1, so we have to subtract one (or rather add vtotal-1
- * to keep the value positive), instead of adding one.
+ * of vtotal-1, so we have to subtract one.
*
* On HSW+ the behaviour of the scanline counter depends on the output
* type. For DP ports it behaves like most other platforms, but on HDMI
@@ -500,7 +498,7 @@ static int intel_crtc_scanline_offset(const struct intel_crtc_state *crtc_state)
* answer that's slightly in the future.
*/
if (DISPLAY_VER(i915) == 2)
- return intel_mode_vtotal(adjusted_mode) - 1;
+ return -1;
else if (HAS_DDI(i915) && intel_crtc_has_type(crtc_state, INTEL_OUTPUT_HDMI))
return 2;
else
--
2.44.1
