diff --git a/drivers/gpu/drm/i915/display/intel_dsb.c b/drivers/gpu/drm/i915/display/intel_dsb.c index db69b1c676f7..4c067bf9ac4c 100644 --- a/drivers/gpu/drm/i915/display/intel_dsb.c +++ b/drivers/gpu/drm/i915/display/intel_dsb.c @@ -170,17 +170,26 @@ static int dsb_scanline_to_hw(struct intel_atomic_state *state, return (scanline + vtotal - intel_crtc_scanline_offset(crtc_state)) % vtotal; } +/* + * Bspec suggests that we should always set DSB_SKIP_WAITS_EN. We have approach + * different from what is explained in Bspec on how flip is considered being + * complete. We are waiting for vblank in DSB and generate interrupt when it + * happens and this interrupt is considered as indication of completion -> we + * definitely do not want to skip vblank wait. We also have concern what comes + * to skipping vblank evasion. I.e. arming registers are latched before we have + * managed writing them. Due to these reasons we are not setting + * DSB_SKIP_WAITS_EN. + */ static u32 dsb_chicken(struct intel_atomic_state *state, struct intel_crtc *crtc) { if (pre_commit_is_vrr_active(state, crtc)) - return DSB_SKIP_WAITS_EN | - DSB_CTRL_WAIT_SAFE_WINDOW | + return DSB_CTRL_WAIT_SAFE_WINDOW | DSB_CTRL_NO_WAIT_VBLANK | DSB_INST_WAIT_SAFE_WINDOW | DSB_INST_NO_WAIT_VBLANK; else - return DSB_SKIP_WAITS_EN; + return 0; } static bool assert_dsb_has_room(struct intel_dsb *dsb)