From 98f974aa3c43f862826d2c05e3844536d0972ed4 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Ville=20Syrj=C3=A4l=C3=A4?= Date: Fri, 2 Dec 2022 15:44:09 +0200 Subject: [PATCH] drm/i915/vrr: Make registers latch in a consitent place on icl/tgl MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Account for the framestart delay when calculating the "pipeline full" value for icl/tgl vrr. This puts the start of vblank (ie. where the double bufferd registers get latched) to a consistent place regardless of what framestart delay value is used. framestart delay does not change where start of vblank occurs in non-vrr mode and I can't see any reason why we'd want different behaviour in vrr mode. Currently framestart delay is always set to 1, and the hardcoded 4 scanlines in the code means we're currently delaying the start of vblank by three extra lines. And with framestart delay set to 4 we'd have no extra delay. Signed-off-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20221202134412.21943-2-ville.syrjala@linux.intel.com Reviewed-by: Manasi Navare --- drivers/gpu/drm/i915/display/intel_vrr.c | 13 ++----------- 1 file changed, 2 insertions(+), 11 deletions(-) diff --git a/drivers/gpu/drm/i915/display/intel_vrr.c b/drivers/gpu/drm/i915/display/intel_vrr.c index 7b1357e..6655dd2c 100644 --- a/drivers/gpu/drm/i915/display/intel_vrr.c +++ b/drivers/gpu/drm/i915/display/intel_vrr.c @@ -153,18 +153,9 @@ intel_vrr_compute_config(struct intel_crtc_state *crtc_state, crtc_state->vrr.guardband = crtc_state->vrr.vmin - adjusted_mode->crtc_vdisplay; } else { - /* - * FIXME: s/4/framestart_delay/ to get consistent - * earliest/latest points for register latching regardless - * of the framestart_delay used? - * - * FIXME: this really needs the extra scanline to provide consistent - * behaviour for all framestart_delay values. Otherwise with - * framestart_delay==4 we will end up extending the min vblank by - * one extra line. - */ crtc_state->vrr.pipeline_full = - min(255, crtc_state->vrr.vmin - adjusted_mode->crtc_vdisplay - 4 - 1); + min(255, crtc_state->vrr.vmin - adjusted_mode->crtc_vdisplay - + crtc_state->framestart_delay - 1); } crtc_state->mode_flags |= I915_MODE_FLAG_VRR; -- 2.7.4