On Tue, 28 May 2024, Ville Syrjala <[email protected]> wrote: > From: Ville Syrjälä <[email protected]> > > 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
*forward Reviewed-by: Jani Nikula <[email protected]> > (intel_crtc_scanline_to_hw()) directions. > > Signed-off-by: Ville Syrjälä <[email protected]> > --- > 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 -- Jani Nikula, Intel
