drm/i915: correctly program the VSYNCSHIFT register
The hw seems to use this to correctly insert the required delay
before/after an even/odd interlaced field. This might also explain
why we need to substract 1 half-line from vtotal - if the hw just
adds the delay programmend in VSYNCSHIFT the total frame time would be
about that too long.
These registers seems to only exist on gen4 and later. For paranoia
also program it to 0 for progressive modes, but according to
documentation the hw should just ignore it in this case.
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Tested-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Tested-by: Alfonso Fiore <alfonso.fiore@gmail.com>
Signed-Off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 1fde35d..34c6345 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -2973,6 +2973,7 @@
I915_WRITE(TRANS_VTOTAL(pipe), I915_READ(VTOTAL(pipe)));
I915_WRITE(TRANS_VBLANK(pipe), I915_READ(VBLANK(pipe)));
I915_WRITE(TRANS_VSYNC(pipe), I915_READ(VSYNC(pipe)));
+ I915_WRITE(TRANS_VSYNCSHIFT(pipe), I915_READ(VSYNCSHIFT(pipe)));
intel_fdi_normal_train(crtc);
@@ -5103,7 +5104,7 @@
int plane = intel_crtc->plane;
int refclk, num_connectors = 0;
intel_clock_t clock, reduced_clock;
- u32 dpll, dspcntr, pipeconf;
+ u32 dpll, dspcntr, pipeconf, vsyncshift;
bool ok, has_reduced_clock = false, is_sdvo = false, is_dvo = false;
bool is_crt = false, is_lvds = false, is_tv = false, is_dp = false;
struct drm_mode_config *mode_config = &dev->mode_config;
@@ -5391,8 +5392,15 @@
/* the chip adds 2 halflines automatically */
adjusted_mode->crtc_vtotal -= 1;
adjusted_mode->crtc_vblank_end -= 1;
- } else
+ vsyncshift = adjusted_mode->crtc_hsync_start
+ - adjusted_mode->crtc_htotal/2;
+ } else {
pipeconf |= PIPECONF_PROGRESSIVE;
+ vsyncshift = 0;
+ }
+
+ if (!IS_GEN3(dev))
+ I915_WRITE(VSYNCSHIFT(pipe), vsyncshift);
I915_WRITE(HTOTAL(pipe),
(adjusted_mode->crtc_hdisplay - 1) |
@@ -5980,8 +5988,13 @@
/* the chip adds 2 halflines automatically */
adjusted_mode->crtc_vtotal -= 1;
adjusted_mode->crtc_vblank_end -= 1;
- } else
+ I915_WRITE(VSYNCSHIFT(pipe),
+ adjusted_mode->crtc_hsync_start
+ - adjusted_mode->crtc_htotal/2);
+ } else {
pipeconf |= PIPECONF_PROGRESSIVE;
+ I915_WRITE(VSYNCSHIFT(pipe), 0);
+ }
I915_WRITE(HTOTAL(pipe),
(adjusted_mode->crtc_hdisplay - 1) |